diff --git a/discussion/index.ndjson b/discussion/index.ndjson
index 48b236ba..1779eddc 100644
--- a/discussion/index.ndjson
+++ b/discussion/index.ndjson
@@ -1,8 +1,8 @@
-{"type":"meta","next_id":{"DSC":44,"AGD":46,"DEC":37,"PLN":136,"LSN":51,"CLSN":1}}
+{"type":"meta","next_id":{"DSC":44,"AGD":46,"DEC":38,"PLN":142,"LSN":52,"CLSN":1}}
{"type":"discussion","id":"DSC-0043","status":"open","ticket":"system-os-cartridge-switch-orchestrator","title":"SystemOS Cartridge Switch Orchestrator","created_at":"2026-07-03","updated_at":"2026-07-03","tags":["runtime","os","lifecycle","game","cartridge","architecture"],"agendas":[{"id":"AGD-0044","file":"AGD-0044-systemos-cartridge-switch-orchestrator.md","status":"open","created_at":"2026-07-03","updated_at":"2026-07-03"}],"decisions":[],"plans":[],"lessons":[]}
{"type":"discussion","id":"DSC-0039","status":"abandoned","ticket":"render-pipeline-family-and-future-3d","title":"Render Pipeline Family and Future 3D","created_at":"2026-06-04","updated_at":"2026-06-04","tags":["gfx","renderer","runtime","architecture","pipeline"],"agendas":[{"id":"AGD-0039","file":"AGD-0039-render-pipeline-family-and-future-3d.md","status":"abandoned","created_at":"2026-06-04","updated_at":"2026-06-04","_override_reason":"User explicitly chose to close this agenda without a new decision because DSC-0038 already established enough architecture for future extension, and 3D is intentionally deferred."}],"decisions":[],"plans":[],"lessons":[],"_override_reason":"User explicitly chose to close this agenda without a new decision because DSC-0038 already established enough architecture for future extension, and 3D is intentionally deferred."}
{"type":"discussion","id":"DSC-0040","status":"done","ticket":"vm-render-parallel-execution-boundary","title":"VM and Render Parallel Execution Boundary","created_at":"2026-06-04","updated_at":"2026-06-06","tags":["runtime","renderer","vm","concurrency","architecture","perf"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0048","file":"discussion/lessons/DSC-0040-vm-render-parallel-execution-boundary/LSN-0048-render-workers-need-a-closed-packet-contract.md","status":"done","created_at":"2026-06-06","updated_at":"2026-06-06"}]}
-{"type":"discussion","id":"DSC-0041","status":"open","ticket":"foreground-stack-game-pause-shell-vm-backed","title":"Foreground Stack, Game Pause, and VM-Backed Shell Coexistence","created_at":"2026-06-05","updated_at":"2026-06-05","tags":["runtime","os","lifecycle","shell","game","vm","foreground","architecture"],"agendas":[{"id":"AGD-0041","file":"AGD-0041-foreground-stack-game-pause-shell-vm-backed.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05"}],"decisions":[],"plans":[],"lessons":[]}
+{"type":"discussion","id":"DSC-0041","status":"in_progress","ticket":"foreground-stack-game-pause-shell-vm-backed","title":"Foreground Stack, Game Pause, and VM-Backed Shell Coexistence","created_at":"2026-06-05","updated_at":"2026-07-03","tags":["runtime","os","lifecycle","shell","game","vm","foreground","architecture"],"agendas":[{"id":"AGD-0041","file":"AGD-0041-foreground-stack-game-pause-shell-vm-backed.md","status":"accepted","created_at":"2026-06-05","updated_at":"2026-07-03"}],"decisions":[{"id":"DEC-0037","file":"DEC-0037-foreground-stack-and-game-pause-contract.md","status":"accepted","created_at":"2026-07-03","updated_at":"2026-07-03","ref_agenda":"AGD-0041"}],"plans":[{"id":"PLN-0136","file":"PLN-0136-route-desktop-home-key-outside-guest-input.md","status":"open","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0037"]},{"id":"PLN-0137","file":"PLN-0137-implement-systemos-foreground-stack-state.md","status":"open","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0037"]},{"id":"PLN-0138","file":"PLN-0138-specify-foreground-pause-and-home-contract.md","status":"open","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0037"]},{"id":"PLN-0139","file":"PLN-0139-validate-game-home-shell-game-end-to-end.md","status":"open","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0037"]},{"id":"PLN-0140","file":"PLN-0140-deliver-game-pause-resume-and-suspension.md","status":"open","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0037"]},{"id":"PLN-0141","file":"PLN-0141-integrate-render-audio-and-input-pause-boundaries.md","status":"open","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0037"]}],"lessons":[]}
{"type":"discussion","id":"DSC-0042","status":"done","ticket":"real-render-worker-establishment","title":"Real Render Worker Establishment","created_at":"2026-06-06","updated_at":"2026-06-20","tags":["runtime","renderer","worker","concurrency","host","hal","architecture"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0049","file":"discussion/lessons/DSC-0042-real-render-worker-establishment/LSN-0049-render-worker-publication-boundary.md","status":"done","created_at":"2026-06-20","updated_at":"2026-06-20"}]}
{"type":"discussion","id":"DSC-0038","status":"done","ticket":"render-frame-packet-boundary","title":"Logical Render Pipelines and Command Packets","created_at":"2026-05-25","updated_at":"2026-06-04","tags":["gfx","renderer","runtime","frame-composer","architecture","ui","pipeline"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0047","file":"discussion/lessons/DSC-0038-render-frame-packet-boundary/LSN-0047-typed-render-submissions-preserve-domain-boundaries.md","status":"done","created_at":"2026-06-04","updated_at":"2026-06-04"}]}
{"type":"discussion","id":"DSC-0035","status":"done","ticket":"task-owned-shell-windows","title":"Agenda - Task-Owned Shell Windows","created_at":"2026-05-15","updated_at":"2026-05-15","tags":["runtime","os","task","window-manager","shell","lifecycle"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0044","file":"discussion/lessons/DSC-0035-task-owned-shell-windows/LSN-0044-task-window-liveness-belongs-to-the-task.md","status":"done","created_at":"2026-05-15","updated_at":"2026-05-15"}]}
@@ -14,7 +14,7 @@
{"type":"discussion","id":"DSC-0001","status":"done","ticket":"legacy-runtime-learn-import","title":"Import legacy runtime learn into discussion lessons","created_at":"2026-03-27","updated_at":"2026-03-27","tags":["migration","tech-debt"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0001","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0001-prometeu-learn-index.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0002","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0002-historical-asset-status-first-fault-and-return-contract.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0003","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0003-historical-audio-status-first-fault-and-return-contract.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0004","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0004-historical-cartridge-boot-protocol-and-manifest-authority.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0005","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0005-historical-game-memcard-slots-surface-and-semantics.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0006","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0006-historical-gfx-status-first-fault-and-return-contract.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0007","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0007-historical-retired-fault-and-input-decisions.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0008","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0008-historical-vm-core-and-assets.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0009","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0009-mental-model-asset-management.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0010","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0010-mental-model-audio.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0011","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0011-mental-model-gfx.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0012","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0012-mental-model-input.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0013","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0013-mental-model-observability-and-debugging.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0014","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0014-mental-model-portability-and-cross-platform.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0015","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0015-mental-model-save-memory-and-memcard.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0016","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0016-mental-model-status-first-and-fault-thinking.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0017","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0017-mental-model-time-and-cycles.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0018","file":"discussion/lessons/DSC-0001-runtime-learn-legacy-import/LSN-0018-mental-model-touch.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"}]}
{"type":"discussion","id":"DSC-0002","status":"done","ticket":"runtime-edge-test-plan","title":"Agenda - Runtime Edge Test Plan","created_at":"2026-03-27","updated_at":"2026-04-21","tags":[],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0037","file":"discussion/lessons/DSC-0002-runtime-edge-test-plan/LSN-0037-domain-gates-must-be-owned-by-the-repository.md","status":"done","created_at":"2026-04-21","updated_at":"2026-04-21"}]}
{"type":"discussion","id":"DSC-0003","status":"open","ticket":"packed-cartridge-loader-pmc","title":"Agenda - Packed Cartridge Loader PMC","created_at":"2026-03-27","updated_at":"2026-03-27","tags":[],"agendas":[{"id":"AGD-0002","file":"AGD-0002-packed-cartridge-loader-pmc.md","status":"open","created_at":"2026-03-27","updated_at":"2026-03-27"}],"decisions":[],"plans":[],"lessons":[]}
-{"type":"discussion","id":"DSC-0004","status":"in_progress","ticket":"system-run-cart","title":"Agenda - System Run Cart","created_at":"2026-03-27","updated_at":"2026-07-03","tags":[],"agendas":[{"id":"AGD-0003","file":"AGD-0003-system-run-cart.md","status":"accepted","created_at":"2026-03-27","updated_at":"2026-07-03"},{"id":"AGD-0045","file":"AGD-0045-systemos-library-root-home-game-launch.md","status":"accepted","created_at":"2026-07-03","updated_at":"2026-07-03"}],"decisions":[{"id":"DEC-0035","file":"DEC-0035-remove-userland-system-run-cart-and-preserve-direct-boot.md","status":"accepted","created_at":"2026-07-03","updated_at":"2026-07-03","ref_agenda":"AGD-0003"},{"id":"DEC-0036","file":"DEC-0036-systemos-games-root-and-home-game-launch.md","status":"accepted","created_at":"2026-07-03","updated_at":"2026-07-03","ref_agenda":"AGD-0045"}],"plans":[{"id":"PLN-0129","file":"PLN-0129-remove-userland-run-cart-abi-surface.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0035"]},{"id":"PLN-0130","file":"PLN-0130-remove-runtime-run-cart-stub-dispatch.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0035"]},{"id":"PLN-0131","file":"PLN-0131-preserve-direct-cartridge-boot-coverage.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0035"]},{"id":"PLN-0132","file":"PLN-0132-specify-games-root-home-launch-contract.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0036"]},{"id":"PLN-0133","file":"PLN-0133-implement-games-root-library-discovery.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0036"]},{"id":"PLN-0134","file":"PLN-0134-wire-home-game-list-launch-flow.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0036"]},{"id":"PLN-0135","file":"PLN-0135-validate-games-root-launch-end-to-end.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03","ref_decisions":["DEC-0036"]}],"lessons":[]}
+{"type":"discussion","id":"DSC-0004","status":"done","ticket":"system-run-cart","title":"Agenda - System Run Cart","created_at":"2026-03-27","updated_at":"2026-07-03","tags":[],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0051","file":"discussion/lessons/DSC-0004-system-run-cart/LSN-0051-launch-authority-belongs-to-systemos.md","status":"done","created_at":"2026-07-03","updated_at":"2026-07-03"}]}
{"type":"discussion","id":"DSC-0005","status":"open","ticket":"system-fault-semantics-and-control-surface","title":"Agenda - System Fault Semantics and Control Surface","created_at":"2026-03-27","updated_at":"2026-03-27","tags":[],"agendas":[{"id":"AGD-0004","file":"AGD-0004-system-fault-semantics-and-control-surface.md","status":"open","created_at":"2026-03-27","updated_at":"2026-03-27"}],"decisions":[],"plans":[],"lessons":[]}
{"type":"discussion","id":"DSC-0006","status":"open","ticket":"vm-owned-random-service","title":"Agenda - VM-Owned Random Service","created_at":"2026-03-27","updated_at":"2026-03-27","tags":[],"agendas":[{"id":"AGD-0005","file":"AGD-0005-vm-owned-random-service.md","status":"open","created_at":"2026-03-27","updated_at":"2026-03-27"}],"decisions":[],"plans":[],"lessons":[]}
{"type":"discussion","id":"DSC-0007","status":"open","ticket":"app-home-filesystem-surface-and-semantics","title":"Agenda - App Home Filesystem Surface and Semantics","created_at":"2026-03-27","updated_at":"2026-03-27","tags":[],"agendas":[{"id":"AGD-0006","file":"AGD-0006-app-home-filesystem-surface-and-semantics.md","status":"open","created_at":"2026-03-27","updated_at":"2026-03-27"}],"decisions":[],"plans":[],"lessons":[]}
diff --git a/discussion/lessons/DSC-0004-system-run-cart/LSN-0051-launch-authority-belongs-to-systemos.md b/discussion/lessons/DSC-0004-system-run-cart/LSN-0051-launch-authority-belongs-to-systemos.md
new file mode 100644
index 00000000..d88d2d7f
--- /dev/null
+++ b/discussion/lessons/DSC-0004-system-run-cart/LSN-0051-launch-authority-belongs-to-systemos.md
@@ -0,0 +1,118 @@
+---
+id: LSN-0051
+ticket: system-run-cart
+title: Launch Authority Belongs to SystemOS
+created: 2026-07-03
+tags: [runtime, systemos, cartridge, launch, abi, home]
+---
+
+## Context
+
+The `system.run_cart` workflow resolved two related questions: whether a guest
+should have an app-callable cartridge launch syscall, and how Home should start
+games from a local library.
+
+The final model removes `system.run_cart` from the userland ABI while preserving
+direct host-controlled cartridge boot. Home launch is restored as a
+system-owned path: the host may provide `--games-root
`, SystemOS/Home
+discovers valid Game directory cartridges, and selecting an entry routes through
+firmware into `LoadCartridge`.
+
+The important distinction is authority. A launch can be a valid product action
+without being a guest capability.
+
+## Key Decisions
+
+### Remove Guest Cartridge Launch
+
+**What:** Prometeu removed `system.run_cart` from the public userland syscall
+surface, generated guest metadata, and runtime dispatch.
+
+**Why:** A guest syscall made cartridge launch look like app-owned navigation.
+That gave userland implied authority over target resolution, lifecycle cleanup,
+failure policy, and system navigation.
+
+**Trade-offs:** Obsolete guest code cannot keep a compatibility stub. The
+runtime instead keeps direct boot as a host/system entrypoint and lets stale
+guest attempts fail through the invalid syscall path.
+
+### Preserve Direct Boot Outside The Guest ABI
+
+**What:** Host, CLI, debugger, tests, and single-game flows continue to boot a
+selected cartridge directly.
+
+**Why:** Direct boot is still essential for development, automation, and future
+single-game distribution. Those flows start with a host-selected target before
+VM execution, so they do not need a guest syscall.
+
+**Trade-offs:** The loader remains reusable, but it is not lifecycle
+orchestration authority. Higher-level transitions must be owned by firmware or
+SystemOS.
+
+### Model Home Launch As A System Action
+
+**What:** `--games-root ` configures a local games library for Home. V1
+discovery scans immediate child directories, keeps only valid Game cartridges,
+and exposes enough internal metadata to launch a selected entry.
+
+**Why:** Home needs a product path for "choose a game and start it", but that
+action belongs to the system profile. SystemOS can present the library and ask
+firmware to enter `LoadCartridge` without reintroducing guest-controlled launch.
+
+**Trade-offs:** V1 intentionally excludes recursive discovery, `.pmc`, non-game
+apps, rich catalog metadata, return-to-Home, and game-to-game switching. Those
+need separate lifecycle and orchestration decisions.
+
+## Patterns and Algorithms
+
+### Authority-Based API Classification
+
+Before exposing an operation to guest/userland code, classify what authority it
+implies. If the operation selects another executable target, changes process
+lifecycle, or controls navigation between system-owned modes, it is probably a
+SystemOS or firmware action rather than an app syscall.
+
+### Separate Selection From Loading
+
+Home owns user selection and presentation. SystemOS owns the launch request.
+Firmware owns the transition into `LoadCartridge`. The cartridge loader remains
+the mechanism that validates and materializes a cartridge, not the authority
+that decides when navigation is allowed.
+
+### Expandable Internal Catalog Records
+
+Home can render a small v1 list while the internal entry retains manifest data,
+title, app id, app version, cartridge path, and discovery metadata. This keeps
+the UI simple without reducing the model to a display-only DTO.
+
+## Pitfalls
+
+### Compatibility Stubs Preserve False Contracts
+
+A syscall that returns success without doing real lifecycle work is worse than
+an absent syscall. It teaches callers that the platform supports app-driven
+launch while hiding that no complete transition happened.
+
+### A Product Flow Is Not Automatically A Guest API
+
+"Home can launch a game" and "a guest can launch a cartridge" are different
+claims. Product behavior should be mapped to the component with the correct
+authority instead of mirrored into the nearest callable ABI.
+
+### Generic Library Roots Prematurely Expand Scope
+
+The first launcher path is a games library, not a marketplace or full app
+catalog. Shell apps, System apps, packages, icons, search, and recursive layouts
+carry separate contracts and should not be smuggled into the v1 games-root path.
+
+## Takeaways
+
+- Cartridge launch is system navigation, not a userland syscall.
+- Direct boot can remain host-controlled without appearing in guest metadata.
+- Home launch should emit a system action and let firmware enter
+ `LoadCartridge`.
+- Loader reuse does not imply loader ownership of lifecycle policy.
+- Keep v1 discovery narrow: immediate child directory cartridges with
+ `app_mode: Game`.
+- Preserve internal catalog metadata even when the Home UI renders only a small
+ subset.
diff --git a/discussion/workflow/agendas/AGD-0003-system-run-cart.md b/discussion/workflow/agendas/AGD-0003-system-run-cart.md
deleted file mode 100644
index b0e1b2ad..00000000
--- a/discussion/workflow/agendas/AGD-0003-system-run-cart.md
+++ /dev/null
@@ -1,202 +0,0 @@
----
-id: AGD-0003
-ticket: system-run-cart
-title: Agenda - System Run Cart
-status: accepted
-created: 2026-03-27
-resolved:
-decision:
-tags: []
----
-
-# Agenda - System Run Cart
-
-## Problema
-
-`system.run_cart` existe na ABI pública, mas hoje não produz efeito real no runtime.
-Isso expõe duas questões: a superfície atual é um placebo e, mesmo quando houver
-fluxo real, rodar cartuchos não deve ser uma operação userland. A autoridade
-para iniciar cartuchos deve pertencer ao sistema/firmware.
-
-Isso cria uma falsa promessa de plataforma:
-
-- o programa consegue declarar e chamar uma operação que aparenta iniciar cartuchos;
-- o loader aceita sua existência;
-- o runtime retorna sucesso vazio;
-- nenhuma troca de cartucho, transição de firmware, validação de alvo ou política de segurança ocorre.
-
-## Dor
-
-- A ABI expõe uma capability de sistema que, na prática, nao existe.
-- Mesmo se implementada, a operação não deve ser uma syscall userland comum:
- apps não devem iniciar cartuchos diretamente.
-- O guest pode acreditar que solicitou uma troca de app quando nada aconteceu.
-- Isso corrói a confiabilidade da plataforma: a interface pública deixa de ser contrato e vira placebo.
-- Qualquer ferramenta, SDK ou documentação construída sobre essa syscall passa a modelar um comportamento inexistente.
-
-## Alvo da Discussao
-
-Definir o contrato real da troca de cartucho iniciada pelo sistema do ponto de vista:
-
-- do guest;
-- do runtime;
-- do firmware;
-- do host/cartridge loader.
-
-Ao final da discussão, deve ficar claro se a superfície atual:
-
-- permanece apenas como mecanismo interno do sistema e sai da ABI userland; ou
-- permanece na ABI somente como superfície privilegiada impossível de chamar por apps comuns; ou
-- sai temporariamente da ABI até existir fluxo fechado.
-
-Esta discussao nao deve depender do fechamento previo do formato `.pmc`.
-Para o primeiro fluxo fechado, `system.run_cart` pode resolver um alvo por
-um loader ja disponivel, incluindo cartucho em diretorio ou fixture de teste.
-O suporte ao artefato empacotado `.pmc` permanece responsabilidade da
-`DSC-0003 / packed-cartridge-loader-pmc` e nao deve bloquear a prova inicial
-de troca `Shell/Hub -> Game`.
-
-Tambem precisa ficar claro que `run_cart`, se existir, nao e o orquestrador da
-troca. No boot direto por linha de comando, carregar um cartucho e simples
-porque o runtime nasce ja apontado para aquele jogo. Com o SO em execucao, o
-caso real e diferente: pode haver um Game residente/rodando, o usuario volta
-para Home, e o sistema decide iniciar outro Game. Nesse caso o SO precisa
-orquestrar fechamento/suspensao descartada do app atual, limpeza de estado,
-resolucao do novo alvo, carregamento e transicao para o proximo estado de
-firmware. O carregador de cartucho e apenas uma etapa desse fluxo.
-
-A direcao preferida e que a orquestracao de troca de cartucho viva no
-SystemOS. Porem, essa agenda nao deve capturar o caso `Game -> Home -> mesmo
-Game`: esse e o escopo da `AGD-0041`, que precisa fechar foreground,
-pausa/suspensao e retorno ao mesmo Game. A troca `Home -> outro Game`, com
-fechamento do jogo atual e carregamento de outro cartucho, pode merecer uma
-agenda propria depois da `AGD-0041`, derivada do contrato de foreground que ela
-fechar.
-
-## O Que Precisa Ser Definido
-
-1. Semântica da operação.
- O que significa "run cart" quando existe SO: trocar imediatamente,
- agendar para o próximo frame, iniciar uma transicao orquestrada pelo
- sistema, ou apenas carregar bytes de cartucho como etapa interna?
-
-2. Origem do alvo.
- Como o guest identifica o cartucho alvo: id numérico, nome canônico, path virtual, handle, manifesto, ou nenhum argumento nesta primeira versão?
- Para v1, uma opcao aceitavel e limitar a resolucao a alvos conhecidos pelo host/test harness e carregaveis pelo loader de diretorio, deixando `.pmc` fora do caminho critico.
-
-3. Modelo de segurança.
- Nenhum app/userland deve chamar `run_cart`. O sistema/firmware e o caminho
- host/CLI/debug devem ser as unicas autoridades para iniciar cartuchos.
- Se apps precisarem solicitar navegacao no futuro, isso deve ser uma
- superficie nova e mediada pelo sistema.
-
-4. Ponto de integração.
- Onde a transição vive: `VirtualMachineRuntime`, firmware, host, SystemOS,
- ou combinação dos três? Para esta agenda, a decisao minima e separar o boot
- direto host/CLI/debug da ABI guest. A orquestracao `Home -> outro Game`
- pertence a `DSC-0043 / AGD-0044`.
-
-5. Efeitos observáveis.
- O que acontece quando um guest tenta chamar a superficie removida, e como
- ferramentas/boot direto continuam carregando cartuchos sem depender de uma
- syscall userland?
-
-6. Contrato de erro.
- Remocao da ABI significa erro de build/declaracao, syscall desconhecida,
- ou bloqueio em registro/capability ate a limpeza completa das declaracoes?
-
-## O Que Necessita Para Resolver
-
-- remocao de `system.run_cart` da ABI userland;
-- definicao de que boot direto continua por caminho host/CLI/debug, nao por
- syscall guest;
-- separacao explicita entre boot direto, loader interno e orquestracao
- `Home -> outro Game` da `DSC-0043 / AGD-0044`;
-- testes garantindo que guest/userland nao pode declarar/chamar `run_cart`;
-- testes garantindo que boot direto de cartucho continua funcional.
-
-## Fora de Escopo
-
-- catálogo completo de apps instalados;
-- UX final do launcher/hub;
-- resolução remota ou download de cartuchos;
-- política de marketplace/distribuição.
-- obrigatoriedade de boot a partir de `.pmc` no primeiro fluxo funcional.
-
-## Sugestao / Recomendacao
-
-Recomendo remover `system.run_cart` da ABI userland para v1. Nao ha necessidade
-de compatibilidade com a superficie atual: ela nao deve permanecer como stub,
-syscall reservada chamavel por guest, nem sucesso vazio.
-
-Rodar cartuchos deve ser uma operacao interna do SystemOS/firmware ou do
-caminho host/CLI/debug, nunca uma syscall de app. O boot direto deve continuar
-existindo porque e o fluxo essencial para testar cartuchos em desenvolvimento e
-tambem representa o modo futuro de executar um jogo unico, como em uma
-integracao tipo Steam.
-
-Recomendo tambem separar dois conceitos:
-
-- **boot direto:** usado por linha de comando/debug, inicia o runtime ja com um
- cartucho alvo e pode continuar simples;
-- **troca via SO:** fluxo orquestrado pelo SystemOS, que fecha o app
- atual quando necessario, limpa estado cartridge-scoped, resolve o proximo
- alvo e so entao chama o carregador.
-
-Essa agenda nao deve implementar o fluxo `Game -> Home -> mesmo Game`; esse
-trabalho pertence a `AGD-0041`. Depois dela, a troca `Home -> outro Game` deve
-ser aberta ou refinada como discussao propria, porque adiciona fechamento do
-jogo atual, limpeza cartridge-scoped, resolucao de novo alvo e falhas de load.
-
-Se a plataforma precisar de uma ação solicitável por apps no futuro, ela deve
-ser modelada separadamente como pedido de navegação mediado pelo sistema, com
-nome e erros que não prometam boot direto.
-
-## Respostas Atuais
-
-- `system.run_cart` deve ser removido da ABI userland.
-- Nao precisamos manter compatibilidade com a superficie atual.
-- Nao deve existir syscall publica para app iniciar cartucho.
-- Boot direto por linha de comando, host, debug ou fluxo equivalente de jogo
- unico deve permanecer.
-- O carregamento interno pode continuar usando loader ja disponivel, incluindo
- cartucho em diretorio/fixture.
-- `.pmc`, catalogo, UX final de launcher e troca `Game A -> Home -> Game B`
- ficam fora desta agenda.
-- Se no futuro apps precisarem pedir navegacao, isso deve ser uma nova
- superficie mediada pelo sistema, nao a volta de `run_cart` userland.
-
-## Critério de Saida Desta Agenda
-
-Esta agenda só pode virar PR de implementação quando existir decisão escrita para:
-
-- retirada da superfície userland atual;
-- preservacao explicita do boot direto host/CLI/debug;
-- comportamento esperado para declaracao/chamada guest obsoleta;
-- fronteira com `AGD-0041` e `AGD-0044`;
-- cobertura minima de testes para remocao userland e boot direto.
-
-## Discussao
-
-- 2026-07-03: A agenda deve ser aberta antes da `AGD-0041` como habilitadora
- de validacao do ciclo `Shell/Hub -> Game`. Ficou definido como premissa de
- agenda que o primeiro `system.run_cart` testavel nao depende de `.pmc`; ele
- pode usar cartucho em diretorio ou fixture resolvida pelo host/test harness.
-- 2026-07-03: Direcao ajustada: `run_cart` nao deve ser uma operacao userland.
- A autoridade de iniciar cartuchos deve pertencer ao sistema/firmware; apps
- podem, no maximo, solicitar navegacao por uma superficie separada e mediada.
-- 2026-07-03: Direcao refinada: `run_cart` simples nao resolve o caso com SO.
- Boot direto por linha de comando continua sendo um caminho simples, mas
- iniciar outro jogo a partir do Home exige um orquestrador do SO/firmware que
- fecha o app atual, limpa estado e so entao carrega o novo cartucho.
-- 2026-07-03: Escopo refinado: `Game -> Home -> mesmo Game` pertence a
- `AGD-0041`. A agenda atual nao deve absorver esse trabalho. Depois da
- `AGD-0041`, a troca `Home -> outro Game` pode ser aberta ou refinada como
- agenda propria para o orquestrador de troca de cartucho no SystemOS.
-- 2026-07-03: A troca `Game A -> Home -> Game B` foi separada para
- `DSC-0043 / AGD-0044`, mantendo esta agenda focada na superficie
- `run_cart`/loader e sua remocao ou restricao como operacao userland.
-- 2026-07-03: Direcao aceita para esta agenda: remover `system.run_cart` da ABI
- userland sem necessidade de compatibilidade, manter boot direto para
- CLI/debug/teste de cartuchos e futuro modo de jogo unico, e deixar navegacao
- mediada por apps para uma superficie futura separada se ela vier a existir.
diff --git a/discussion/workflow/agendas/AGD-0041-foreground-stack-game-pause-shell-vm-backed.md b/discussion/workflow/agendas/AGD-0041-foreground-stack-game-pause-shell-vm-backed.md
index 973f74e2..65520de4 100644
--- a/discussion/workflow/agendas/AGD-0041-foreground-stack-game-pause-shell-vm-backed.md
+++ b/discussion/workflow/agendas/AGD-0041-foreground-stack-game-pause-shell-vm-backed.md
@@ -2,10 +2,10 @@
id: AGD-0041
ticket: foreground-stack-game-pause-shell-vm-backed
title: Foreground Stack, Game Pause, and VM-Backed Shell Coexistence
-status: open
+status: accepted
created: 2026-06-05
-resolved:
-decision:
+resolved: 2026-07-03
+decision: DEC-0037
tags: [runtime, os, lifecycle, shell, game, vm, foreground, architecture]
---
@@ -99,16 +99,49 @@ Isso preserva o ciclo `Game -> Home/Shell -> Game` sem transformar o runtime em
## Perguntas em Aberto
-- [ ] Qual e o nome canonico dos estados de Game fora do foreground: `Paused`, `Suspended`, ambos, ou outro?
-- [ ] Ao apertar Home, o Game deve receber um evento/interrupt/trap de pausa antes de parar de executar?
-- [ ] O Hub e um Shell especial sempre presente ou uma task Shell comum?
-- [ ] Um app Shell VM-backed pode substituir o Hub no foreground ou o Hub permanece como owner raiz?
-- [ ] Quando o Shell VM-backed fecha, o retorno vai sempre para Hub ou pode voltar diretamente ao Game?
-- [ ] O input do Game e drenado/limpo ao pausar e ao retomar?
-- [ ] Audio do Game pausa junto com a VM ou tem politica propria?
-- [ ] Existe limite de memoria/residencia para manter Game pausado enquanto Shell app roda?
-- [ ] O retorno ao Game exige novo frame antes de trocar a superficie, ou a tela pode manter Hub/Shell ate a primeira submission valida?
-- [ ] Quais eventos de lifecycle precisam ser visiveis para firmware, OS, VM e host?
+- [x] Qual e o nome canonico dos estados de Game fora do foreground: `Paused`, `Suspended`, ambos, ou outro?
+- [x] Ao apertar Home, o Game deve receber um evento/interrupt/trap de pausa antes de parar de executar?
+- [x] O Hub e um Shell especial sempre presente ou uma task Shell comum?
+- [x] Um app Shell VM-backed pode substituir o Hub no foreground ou o Hub permanece como owner raiz?
+- [x] Quando o Shell VM-backed fecha, o retorno vai sempre para Hub ou pode voltar diretamente ao Game?
+- [x] O input do Game e drenado/limpo ao pausar e ao retomar?
+- [x] Audio do Game pausa junto com a VM ou tem politica propria?
+- [x] Existe limite de memoria/residencia para manter Game pausado enquanto Shell app roda?
+- [x] O retorno ao Game exige novo frame antes de trocar a superficie, ou a tela pode manter Hub/Shell ate a primeira submission valida?
+- [x] Quais eventos de lifecycle precisam ser visiveis para firmware, OS, VM e host?
+
+## Resolucao
+
+Fica aceito o modelo `Game -> Home/Shell -> mesmo Game` com foreground unico e
+residencia limitada:
+
+- somente um Game pode estar residente por vez;
+- somente um Shell pode ser foreground por vez;
+- Hub e o Shell root/especial e permanece owner raiz/back-stack;
+- um Shell VM-backed pode assumir o foreground visual, mas segue lifecycle de
+ Shell e nao herda politica de game loop;
+- fechar um Shell VM-backed retorna ao Hub em v1;
+- background execution real fica fora de escopo;
+- no host desktop, `Esc` e a tecla principal para solicitar Home/SystemOS e a
+ tecla fisica `Home` pode existir como alias;
+- a acao Home/SystemOS e interceptada pelo host/SystemOS e nao entra no pad
+ logico visivel ao Game;
+- `Paused` e o estado/evento cooperativo visivel ao Game;
+- `Suspended` e o estado operacional imposto pelo OS/scheduler;
+- ao sair do foreground, o OS notifica o Game para pausar e concede um budget
+ curto de reacao;
+- se o Game nao reagir ao pause dentro do budget, o OS suspende a VM mesmo
+ assim;
+- ao retornar, o OS reativa a VM, notifica o Game para resume/foreground
+ restore e permite que o Game sincronize antes de voltar ao gameplay;
+- input pendente do Game e drenado/limpo nas fronteiras de pause/resume;
+- audio do Game pausa junto com a VM em v1;
+- retorno ao Game deve manter Hub/Shell visivel ate a primeira render submission
+ valida do Game retomado;
+- render ownership muda junto com o foreground owner e invalida submissions
+ antigas via epoch/generation;
+- firmware observa transicoes macro; OS observa lifecycle completo; VM observa
+ pause/resume; host observa owner/render epoch e estado de apresentacao.
## Criterio para Encerrar
@@ -124,3 +157,22 @@ A agenda pode ser encerrada quando tivermos uma decisao clara sobre:
## Discussao
- 2026-06-05: Agenda criada a partir da `DSC-0040`, quando o caso de Shell VM-backed aberto sobre um Game pausado mostrou que a discussao pertence ao lifecycle/SystemOS, nao apenas ao render worker.
+- 2026-07-03: Direcao provisoria aceita para as perguntas 2-10:
+ Game deve receber evento de pausa com budget curto antes da suspensao; Hub e
+ Shell root/especial; Shell VM-backed pode assumir foreground visual, mas Hub
+ permanece como owner raiz/back-stack; fechar Shell VM-backed retorna ao Hub em
+ v1; input do Game deve ser drenado/limpo em pause/resume; audio do Game pausa
+ junto com VM em v1; apenas um Game pausado residente e permitido; retorno ao
+ Game deve manter Hub/Shell visivel ate a primeira submission valida; firmware
+ ve transicoes macro, OS ve lifecycle completo, VM ve pause/resume, host ve
+ owner/render epoch e estado de apresentacao.
+- 2026-07-03: Pergunta 1 permanece aberta para esclarecer se `Paused` e
+ `Suspended` sao estados distintos, nomes para camadas diferentes, ou se v1
+ deve expor somente um deles.
+- 2026-07-03: Direcao proposta para pergunta 1: `Paused` e o estado/evento
+ cooperativo visivel ao Game; `Suspended` e o estado operacional imposto pelo
+ OS. Ao sair do foreground, o OS notifica o Game para pausar e concede um
+ budget curto de reacao; se o Game nao reagir, o OS suspende a VM mesmo assim.
+ Ao retornar, o OS notifica o Game antes de recoloca-lo no foreground visual,
+ permitindo sincronizacao/revalidacao. O Game nao controla a suspensao, mas
+ pode observar `pause`/`resume` para ajustar seu estado interno.
diff --git a/discussion/workflow/agendas/AGD-0045-systemos-library-root-home-game-launch.md b/discussion/workflow/agendas/AGD-0045-systemos-library-root-home-game-launch.md
deleted file mode 100644
index 3f1980f7..00000000
--- a/discussion/workflow/agendas/AGD-0045-systemos-library-root-home-game-launch.md
+++ /dev/null
@@ -1,161 +0,0 @@
----
-id: AGD-0045
-ticket: system-run-cart
-title: SystemOS Library Root and Home Game Launch
-status: accepted
-created: 2026-07-03
-resolved:
-decision:
-tags: [runtime, os, hub, cartridge, launcher, library, game, architecture]
----
-
-## Contexto
-
-A `DEC-0035` fechou que `system.run_cart` nao deve existir como syscall
-userland e que boot direto por host/CLI/debug deve permanecer.
-
-Isso resolveu a autoridade negativa, mas ainda nao resolveu a experiencia
-desejada para o SO: apontar o runtime para um diretorio raiz de biblioteca,
-fazer a Home listar os cartuchos encontrados ali e permitir que o usuario clique
-em um jogo para carrega-lo.
-
-O objetivo pratico e um "Switch feio": uma lista simples na Home, sem UX final,
-sem marketplace e sem catalogo rico, mas capaz de provar que o SO, e nao o
-guest, escolhe e carrega um cartucho a partir de uma biblioteca local.
-
-## Problema
-
-Hoje temos dois caminhos separados:
-
-- boot direto por `--run ` funciona e carrega um cartucho unico;
-- Hub/Home existe, mas mostra acoes fixas de Shell nativo e nao lista jogos de
- uma biblioteca real.
-
-Sem uma biblioteca de cartuchos visivel para o SO, o usuario nao consegue
-iniciar jogos a partir da Home. Isso deixa a agenda `system-run-cart` incompleta
-do ponto de vista de produto: removemos o `run_cart` userland, mas ainda falta a
-alternativa correta, que e o SO iniciar cartuchos por acao de usuario.
-
-## Pontos Criticos
-
-- O root da biblioteca deve ser fornecido pelo host como `--games-root `.
-- O scan inicial deve cobrir subdiretorios imediatos com `manifest.json`.
-- O loader de diretorio existente deve continuar sendo a autoridade para validar
- cartucho completo; a biblioteca pode ler metadados minimos para listagem.
-- A Home pode mostrar uma lista feia/clicavel; polimento visual fica fora.
-- O clique em um Game deve iniciar `LoadCartridge` pelo firmware/SystemOS, nao
- por syscall guest.
-- V1 nao precisa tratar retorno de um Game para Home, porque isso pertence a
- `AGD-0041`.
-- `.pmc`, outros tipos de app, catalogo remoto, marketplace, icones, busca e
- metadados ricos ficam fora.
-
-## Opcoes
-
-### Opcao A - Biblioteca apenas para listagem
-
-- **Abordagem:** adicionar `--games-root`, escanear manifestos e mostrar jogos
- na Home, mas sem permitir launch ainda.
-- **Pro:** baixa complexidade; prova descoberta/catalogo local.
-- **Contra:** nao entrega o objetivo principal de carregar jogo pela Home.
-- **Manutenibilidade:** boa, mas valor funcional limitado.
-
-### Opcao B - Home lista biblioteca e carrega Game quando nao ha Game ativo
-
-- **Abordagem:** adicionar `--games-root`, escanear cartuchos locais, renderizar
- lista simples na Home e permitir clique para carregar um Game via
- `LoadCartridge`. A primeira versao cobre Home inicial/sem Game residente.
-- **Pro:** entrega o fluxo desejado sem abrir troca completa entre jogos.
-- **Contra:** exige passar biblioteca/acao selecionada entre host, Hub,
- firmware e loader.
-- **Manutenibilidade:** boa se a fronteira ficar clara: biblioteca descobre,
- Hub escolhe, firmware carrega.
-
-### Opcao C - Biblioteca mais troca completa entre jogos
-
-- **Abordagem:** Home lista biblioteca e tambem permite `Game A -> Home ->
- Game B` ja no primeiro passo.
-- **Pro:** cobre a experiencia final.
-- **Contra:** mistura biblioteca com pausa, fechamento, cleanup e falha de load;
- depende de `AGD-0041` e `AGD-0044`.
-- **Manutenibilidade:** baixa para v1.
-
-## Sugestao / Recomendacao
-
-Recomendo a Opcao B.
-
-O v1 deve permitir:
-
-- host recebe `--games-root `;
-- o SO/Hub recebe uma lista de cartuchos descobertos;
-- a Home mostra uma lista simples/clicavel de jogos;
-- clicar em um Game carrega o cartucho via firmware `LoadCartridge`;
-- boot direto por `--run ` continua separado e intacto;
-- nenhum guest/app chama `run_cart`;
-- o escopo v1 acontece na Home inicial; retorno de Game para Home fica para
- `AGD-0041`, e troca `Game A -> Home -> Game B` fica para `AGD-0044`.
-
-Detalhes aceitos para v1:
-
-- scan apenas de subdiretorios imediatos;
-- somente cartuchos `app_mode: Game`;
-- `.pmc` fica para futuro;
-- cartuchos invalidos sao logados e omitidos da lista;
-- o modelo interno deve ser uma entry de biblioteca expansivel, nao apenas um
- summary de UI. A entry pode manter o manifest carregado em memoria, path
- interno necessario para launch e metadados operacionais como instante de
- descoberta/instalacao. A UI v1 mostra apenas `title`, `app_id` e
- `app_version`, mas futuros metadados ingeridos pela biblioteca poderao ser
- usados pelo catalogo e pela propria UI;
-- clique carrega imediatamente, sem confirmacao;
-- falha de load volta para Home e registra log/erro.
-
-Essa agenda deve produzir a alternativa correta ao `run_cart` userland: uma
-acao de sistema, iniciada pela Home, que carrega cartucho escolhido pelo usuario
-a partir de uma biblioteca local.
-
-## Perguntas em Aberto
-
-- [x] O argumento deve se chamar `--games-root`.
-- [x] A biblioteca deve escanear apenas subdiretorios imediatos.
-- [x] A listagem v1 deve incluir apenas `app_mode: Game`.
-- [x] O scan deve logar cartuchos invalidos e omiti-los da lista.
-- [x] O Hub/SystemOS deve receber uma entry de biblioteca expansivel, capaz de
- manter o manifest carregado, path interno para launch e metadados
- operacionais como timestamp de descoberta/instalacao. A UI v1 so precisa
- mostrar `title`, `app_id` e `app_version`.
-- [x] O clique deve carregar imediatamente, sem confirmacao.
-- [x] Se um cartucho falha ao carregar, o sistema volta para Home e registra
- erro/log.
-- [x] Retorno de Game para Home nao pertence a esta agenda; fica para
- `AGD-0041`.
-- [x] O teste minimo deve provar o fluxo `games-root -> Home list -> click ->
- LoadCartridge -> GameRunning`?
-
-## Criterio para Encerrar
-
-A agenda pode virar decisao quando estiver claro:
-
-- nome e semantica do argumento de host para root da biblioteca;
-- escopo do scan e metadados minimos;
-- fronteira entre biblioteca, Hub, firmware e loader;
-- politica v1 para cartuchos invalidos;
-- regra v1 para launch quando nao ha Game ativo;
-- fronteira explicita com `AGD-0041` e `AGD-0044`;
-- testes minimos para discovery e launch pela Home.
-
-## Discussao
-
-- 2026-07-03: Agenda criada como continuacao da `DSC-0004` apos a `DEC-0035`.
- A decisao anterior removeu `run_cart` userland; esta agenda define o caminho
- correto para o SO/Home carregar jogos a partir de uma biblioteca local.
-- 2026-07-03: Respostas aceitas: usar `--games-root`, escanear apenas
- subdiretorios imediatos, listar somente Games, deixar `.pmc` e outros apps
- para depois, logar/omitir invalidos, usar summary com `title`, `app_id` e
- `app_version`, carregar imediatamente no clique, e deixar retorno para Home
- sob responsabilidade da `AGD-0041`.
-- 2026-07-03: Modelo de dados refinado: a biblioteca deve produzir entries
- expansíveis, nao somente summaries de UI. Cada entry pode manter manifest em
- memoria, path interno de launch e metadados operacionais como timestamp de
- descoberta/instalacao; a UI v1 escolhe quais campos mostrar, mas o modelo
- deve permitir que metadados futuros sejam ingeridos e usados pelo catalogo/UI.
diff --git a/discussion/workflow/decisions/DEC-0035-remove-userland-system-run-cart-and-preserve-direct-boot.md b/discussion/workflow/decisions/DEC-0035-remove-userland-system-run-cart-and-preserve-direct-boot.md
deleted file mode 100644
index 5e212b26..00000000
--- a/discussion/workflow/decisions/DEC-0035-remove-userland-system-run-cart-and-preserve-direct-boot.md
+++ /dev/null
@@ -1,136 +0,0 @@
----
-id: DEC-0035
-ticket: system-run-cart
-title: Remove Userland system.run_cart and Preserve Direct Boot
-status: accepted
-created: 2026-07-03
-ref_agenda: AGD-0003
-tags: []
----
-
-## Status
-
-Accepted.
-
-## Contexto
-
-`system.run_cart` existe na ABI publica, mas nao possui comportamento real de
-troca de cartucho. Isso cria uma falsa promessa: um guest pode declarar/chamar
-uma operacao que aparenta iniciar outro cartucho, enquanto o runtime retorna
-sucesso vazio ou nao executa uma transicao completa.
-
-A discussao fechou tres separacoes:
-
-- boot direto por host/CLI/debug e necessario e deve permanecer;
-- apps/userland nao devem iniciar cartuchos diretamente;
-- troca `Game A -> Home -> Game B` exige um orquestrador de SystemOS proprio,
- separado em `DSC-0043 / AGD-0044`.
-
-`AGD-0041` permanece responsavel por `Game -> Home -> mesmo Game`, foreground,
-pausa/suspensao e retorno ao mesmo Game.
-
-## Decisao
-
-`system.run_cart` MUST be removed from the userland guest ABI.
-
-No app, cartridge, Shell app, or other userland guest code MAY directly request
-cartridge boot through `system.run_cart`.
-
-The platform MUST NOT preserve compatibility for the current userland
-`system.run_cart` surface. It MUST NOT remain as a callable stub, reserved
-guest syscall that returns success, or capability-gated userland escape hatch.
-
-Direct boot MUST remain supported through host/CLI/debug or equivalent
-single-game launch paths. This direct boot path is a host/system entrypoint,
-not a guest syscall.
-
-Internal cartridge loading MAY continue to use the existing loader path,
-including directory cartridges and test fixtures. `.pmc` support is not required
-by this decision.
-
-If apps ever need to request navigation in the future, that MUST be designed as
-a separate SystemOS-mediated surface with different naming and semantics. It
-MUST NOT reintroduce userland `run_cart` as direct cartridge boot.
-
-## Rationale
-
-Direct cartridge boot is essential for development, debugging, automated tests,
-and future distribution modes where the runtime launches as a single game. That
-use case does not require a guest-visible syscall.
-
-Userland cartridge boot would give app code authority over system navigation,
-lifecycle, cleanup, target resolution, and failure policy. Those concerns belong
-to SystemOS/firmware and later to the cartridge switch orchestrator, not to a VM
-guest syscall.
-
-Keeping a stub or compatibility surface would preserve the current ambiguity.
-The public ABI should not advertise an operation that either does nothing or
-looks like direct app-controlled navigation.
-
-## Invariantes / Contrato
-
-- Guest/userland MUST NOT expose or call `system.run_cart`.
-- The public syscall registry, declarations, generated bindings, and docs MUST
- stop presenting `system.run_cart` as an app-callable operation.
-- Booting a cartridge directly MUST remain available from host/CLI/debug flows.
-- Direct boot MUST enter the runtime with a selected cartridge target; it MUST
- NOT depend on a guest syscall issued after VM startup.
-- Loader code MAY remain reusable by host/firmware/SystemOS internals.
-- Loader code MUST NOT become lifecycle orchestration authority.
-- `Game -> Home -> same Game` remains owned by `AGD-0041`.
-- `Game A -> Home -> Game B` remains owned by `DSC-0043 / AGD-0044`.
-- `.pmc`, app catalog, launcher UX, marketplace/distribution, and full cartridge
- replacement under Home are outside this decision.
-
-## Impactos
-
-- **Spec / ABI:** remove or retire `system.run_cart` from the userland syscall
- surface. Any syscall table, PBS declarations, generated metadata, or docs
- must stop advertising it to apps.
-- **Runtime / VM:** guest dispatch must no longer treat `system.run_cart` as a
- valid userland operation. If obsolete bytecode or declarations still reach the
- runtime during migration, they must fail explicitly rather than report success.
-- **Firmware / Host:** direct boot remains supported for command-line,
- debugger, test harness, and future single-game launch flows.
-- **SystemOS:** no new cart-switch orchestrator is required by this decision.
- That work is deferred to `DSC-0043 / AGD-0044`.
-- **Tooling:** tools must continue to support direct cartridge launch for
- development and test workflows, without relying on a guest syscall.
-- **Tests:** coverage must prove both sides: userland cannot declare/call
- `system.run_cart`, and direct boot of a cartridge still works.
-
-## Alternativas Descartadas
-
-- **Implement `system.run_cart` as a normal syscall:** rejected because it gives
- userland direct navigation authority and mixes guest execution with system
- lifecycle.
-- **Keep a compatibility stub:** rejected because no compatibility is required
- and a stub preserves the false contract.
-- **Make `system.run_cart` privileged but still guest-visible:** rejected for v1
- because it keeps the ambiguous idea that some guest profile may directly boot
- cartuchos.
-- **Implement full `Home -> another Game` now:** rejected for this decision; it
- requires SystemOS orchestration after the `AGD-0041` foreground contract.
-
-## Referencias
-
-- Agenda: `AGD-0003`
-- Foreground/pause scope: `AGD-0041`
-- Future cartridge switch orchestrator: `DSC-0043 / AGD-0044`
-- Related lessons: `LSN-0041` SystemOS lifecycle authority, `LSN-0042`
- SystemOS service ownership boundary, `LSN-0043` SystemOS domain facades.
-
-## Propagacao Necessaria
-
-- Remove `SystemRunCart` from userland ABI declarations and generated syscall
- metadata.
-- Remove or rewrite runtime dispatch paths that return success for
- `system.run_cart`.
-- Preserve host/CLI/debug direct boot paths and add regression tests for them.
-- Add negative tests for guest/userland declaration or call attempts.
-- Update any documentation/spec text that describes `system.run_cart` as
- app-callable.
-
-## Revision Log
-
-- 2026-07-03: Initial draft from `AGD-0003`.
diff --git a/discussion/workflow/decisions/DEC-0036-systemos-games-root-and-home-game-launch.md b/discussion/workflow/decisions/DEC-0036-systemos-games-root-and-home-game-launch.md
deleted file mode 100644
index ed7eda2c..00000000
--- a/discussion/workflow/decisions/DEC-0036-systemos-games-root-and-home-game-launch.md
+++ /dev/null
@@ -1,156 +0,0 @@
----
-id: DEC-0036
-ticket: system-run-cart
-title: SystemOS Games Root and Home Game Launch
-status: accepted
-created: 2026-07-03
-ref_agenda: AGD-0045
-tags: []
----
-
-## Status
-
-Accepted.
-
-## Contexto
-
-`DEC-0035` removed `system.run_cart` from the userland guest ABI and preserved
-direct host/CLI/debug cartridge boot. That decision intentionally did not
-deliver the Home/SO product flow: pointing PROMETEU at a local games directory,
-listing available games in Home, and launching a selected game by user action.
-
-This decision defines the first system-owned replacement for userland
-`run_cart`: a local games-root library discovered by the host/SystemOS and
-exposed through a simple Home UI.
-
-## Decisao
-
-PROMETEU MUST support a host-provided games library root through
-`--games-root `.
-
-The games root is a directory containing game cartridge directories as immediate
-children. V1 MUST scan only immediate child directories. Recursive discovery is
-out of scope.
-
-The v1 games library MUST include only cartridges whose manifest declares
-`app_mode: Game`. Shell/System apps, `.pmc` packages, remote catalogs,
-marketplace/distribution metadata, rich icons, search, and non-game apps are out
-of scope.
-
-The library MUST produce expandable internal entries, not UI-only summaries.
-Each entry MUST retain enough internal data to launch the cartridge and to grow
-as a catalog model. At minimum, each entry MUST include:
-
-- loaded manifest data;
-- `title`;
-- `app_id`;
-- `app_version`;
-- internal cartridge path;
-- operational discovery metadata, including a timestamp or equivalent discovery
- marker.
-
-The Home UI v1 SHOULD display only `title`, `app_id`, and `app_version`. It MAY
-hide path and operational metadata.
-
-Invalid cartridge candidates MUST be logged and omitted from the Home game list.
-
-Selecting a listed Game in Home MUST immediately request a system-owned launch
-through firmware/SystemOS, resulting in `LoadCartridge` for that cartridge. This
-MUST NOT use a guest syscall and MUST NOT reintroduce userland `run_cart`.
-
-If launch fails, the machine MUST return to or remain in Home and record an
-error/log. A polished error UI is out of scope.
-
-Booting directly with `--run ` MUST remain separate and unchanged.
-
-Returning from a running Game to Home is outside this decision and belongs to
-`AGD-0041`. Switching from `Game A -> Home -> Game B` after a game is already
-active belongs to `DSC-0043 / AGD-0044`.
-
-## Rationale
-
-The previous `run_cart` surface was wrong because it made cartridge launch look
-like an app/userland capability. The desired behavior is still valid, but the
-authority must live in the system: Home presents available games and the
-firmware/SystemOS loads the selected cartridge.
-
-Using `--games-root` keeps the v1 product model honest: this is a local game
-library, not a general app root. Other app types can be introduced later without
-forcing the first launcher model to pretend it is a full marketplace.
-
-Immediate child scanning keeps discovery deterministic and testable. `.pmc` and
-recursive layouts can be added after the directory-cartridge path is proven.
-
-An expandable entry model avoids prematurely freezing the UI shape as the data
-model. The UI is intentionally simple, but the catalog model needs room for
-future metadata such as package origin, installation/discovery timestamps, rich
-presentation fields, and packaged cartridge details.
-
-## Invariantes / Contrato
-
-- `--games-root ` is the v1 host argument for a local games library.
-- The games root is Game-only in v1.
-- Discovery scans immediate child directories only.
-- Directory candidates without valid Game cartridge metadata are logged and
- omitted.
-- Library entries are internal catalog records, not direct UI DTOs.
-- The UI v1 displays a simple clickable list and may show only `title`,
- `app_id`, and `app_version`.
-- The internal entry retains cartridge path and loaded manifest data for launch.
-- Home selection is a system action that enters firmware/SystemOS loading. It is
- not a guest syscall.
-- `--run ` direct boot remains independent from `--games-root`.
-- Return-to-Home and game-to-game switching are not implemented by this
- decision.
-
-## Impactos
-
-- **Host:** add a `--games-root ` argument and pass the resolved root into
- runtime/firmware/SystemOS initialization.
-- **SystemOS / Hub:** add a local game library model and expose entries to Home.
- Home must render a minimal clickable list and emit a system-owned launch
- action for a selected entry.
-- **Firmware:** consume the Home launch action and transition to
- `LoadCartridge` with the selected cartridge path.
-- **Loader:** continue to validate complete directory cartridges. Discovery may
- read manifest metadata, but full launch still uses the existing loader.
-- **Runtime / VM:** no userland ABI is added. No guest syscall participates in
- launch.
-- **Specs / Docs:** document `--games-root`, Game-only v1 discovery, and the
- distinction between direct boot, games library launch, and future game
- switching.
-- **Tests:** cover discovery, invalid omission/logging, Home action emission,
- and the end-to-end path from games root selection to `GameRunning`.
-
-## Alternativas Descartadas
-
-- **List only, no launch:** rejected because it does not satisfy the product
- goal of starting games from Home.
-- **General app root:** rejected for v1 because Shell/System apps need separate
- lifecycle and UI contracts.
-- **Recursive discovery:** rejected for v1 to keep semantics deterministic.
-- **`.pmc` discovery:** rejected for v1 because packed cartridge loading is a
- separate open agenda.
-- **Game-to-game switch now:** rejected because it depends on foreground and
- cartridge-switch orchestration work in `AGD-0041` and `AGD-0044`.
-
-## Referencias
-
-- Source agenda: `AGD-0045`
-- Userland run-cart removal: `DEC-0035`
-- Foreground/Home return scope: `AGD-0041`
-- Future cartridge switch orchestration: `DSC-0043 / AGD-0044`
-
-## Propagacao Necessaria
-
-- Add or update runtime specs for games-root discovery and Home launch.
-- Add host CLI argument plumbing for `--games-root`.
-- Add a catalog/library entry model.
-- Add Hub/Home list rendering and click handling.
-- Add firmware/SystemOS action routing to `LoadCartridge`.
-- Add tests for discovery, invalid candidates, action emission, and
- `games-root -> Home click -> GameRunning`.
-
-## Revision Log
-
-- 2026-07-03: Initial draft from `AGD-0045`.
diff --git a/discussion/workflow/decisions/DEC-0037-foreground-stack-and-game-pause-contract.md b/discussion/workflow/decisions/DEC-0037-foreground-stack-and-game-pause-contract.md
new file mode 100644
index 00000000..5e2d8765
--- /dev/null
+++ b/discussion/workflow/decisions/DEC-0037-foreground-stack-and-game-pause-contract.md
@@ -0,0 +1,191 @@
+---
+id: DEC-0037
+ticket: foreground-stack-game-pause-shell-vm-backed
+title: Foreground Stack and Game Pause Contract
+status: accepted
+created: 2026-07-03
+ref_agenda: AGD-0041
+tags: [runtime, os, lifecycle, shell, game, vm, foreground, architecture]
+---
+
+## Status
+
+Accepted.
+
+## Contexto
+
+`AGD-0041` defines the minimum lifecycle contract for `Game -> Home/Shell ->
+same Game`.
+
+The issue is not only rendering. The render worker needs a single valid visual
+owner, but SystemOS must decide which VMs may exist, which owner receives input,
+which owner may tick, what happens to a Game when Home takes foreground, and how
+a VM-backed Shell app coexists with a paused Game.
+
+This decision builds on:
+
+- `DSC-0031`: runtime mode separation between Game and System/Shell;
+- `DSC-0032`: SystemOS lifecycle/process/task authority;
+- `DSC-0035`: task-owned Shell windows and Shell liveness;
+- `DSC-0036`: Hub/Shell as a lifecycle proving surface;
+- `DSC-0040`: render ownership/epoch and stale submission invalidation.
+
+## Decisao
+
+PROMETEU MUST use a single-foreground-owner model for v1.
+
+At most one Game MAY be resident at a time. At most one Shell app MAY be the
+foreground visual owner at a time.
+
+The Hub MUST be treated as the root/special Shell owner for Home. A VM-backed
+Shell app MAY replace the Hub as the foreground visual owner, but the Hub
+remains the root/back-stack controller. In v1, closing a VM-backed Shell app
+MUST return to Hub/Home, not directly to the Game.
+
+When the user requests Home while a Game is running, SystemOS MUST start a
+cooperative pause transition:
+
+- the Game receives a pause lifecycle notification;
+- the Game is given a short bounded budget to react;
+- after that budget, SystemOS MAY suspend the Game VM even if the Game did not
+ cooperate;
+- the Game remains resident but MUST NOT receive normal gameplay ticks, normal
+ game input, or frame pacing while suspended;
+- the Shell/Hub foreground owner MAY execute according to Shell lifecycle rules.
+
+`Paused` is the Game-visible lifecycle state/event. `Suspended` is the
+OS/scheduler operational state. A Game may observe pause/resume, but it MUST NOT
+control whether the OS suspends or resumes its VM.
+
+When returning to the same Game, SystemOS MUST reactivate the Game VM and send a
+resume or foreground-restore lifecycle notification before restoring visual
+foreground. The Game MAY remain internally paused while it synchronizes. The
+system MUST keep Hub/Shell visible until the resumed Game produces a valid new
+render submission for the current ownership epoch.
+
+Input pending for the Game MUST be drained or cleared across pause/resume
+boundaries. Game audio MUST pause with the Game VM in v1. Independent background
+audio policy is out of scope.
+
+Render ownership MUST move with the foreground owner. Foreground transitions
+MUST invalidate stale render submissions through ownership epoch/generation so
+old Game frames cannot be presented after Shell takes foreground, and old Shell
+frames cannot be presented after the Game resumes.
+
+On the desktop host, `Esc` MUST be the primary keyboard request for Home/SystemOS.
+The physical `Home` key MAY be supported as an alias. This Home request is a
+host/SystemOS control action and MUST NOT be exposed as a normal guest pad
+button or userland input capability.
+
+Real background execution, multiple resident Games, multiple foreground Shells,
+Game-to-Game switching, Shell app persistence policy, memory eviction policy,
+and rich multitasking are out of scope for this decision.
+
+## Rationale
+
+The chosen model preserves the expected console-like flow: a Game can be
+paused, Home can run, Shell apps can open, and the same Game can resume without
+turning the runtime into a general multitasking scheduler.
+
+Separating `Paused` from `Suspended` keeps authority clear. `Paused` is the
+contract the Game can observe and react to. `Suspended` is the OS mechanism that
+prevents the paused Game from continuing to consume ticks, input, audio, and
+render ownership while another owner is foreground.
+
+Keeping Hub as root/back-stack prevents VM-backed Shell apps from becoming
+independent lifecycle roots. Returning to Hub before resuming Game keeps v1
+navigation deterministic and leaves more complex direct-return behavior for a
+future decision.
+
+Keeping Hub/Shell visible until the Game submits a new valid frame avoids
+presenting stale pixels from the previous Game epoch. This aligns lifecycle
+state with the render ownership model from `DSC-0040`.
+
+Using `Esc` as desktop Home makes the control available on compact keyboards.
+Supporting the physical `Home` key as an alias is acceptable, but the portable
+contract cannot depend on it.
+
+## Invariantes / Contrato
+
+- There is exactly one foreground visual owner at a time.
+- V1 supports at most one resident Game.
+- V1 supports at most one foreground Shell app.
+- Hub/Home is the root Shell owner and back-stack controller.
+- VM-backed Shell apps follow Shell lifecycle, not Game loop lifecycle.
+- A paused Game may remain resident, but a suspended Game does not receive
+ normal gameplay ticks, normal game input, or frame pacing.
+- Pause/resume are cooperative Game-visible lifecycle events.
+- Suspend/resume scheduling authority belongs to SystemOS.
+- SystemOS may suspend a Game after the pause budget even if the Game does not
+ cooperate.
+- Input is cleared or barriered across Game pause/resume boundaries.
+- Game audio pauses with the Game VM in v1.
+- Foreground transitions advance render ownership epoch/generation.
+- Visual foreground returns to Game only after a valid current-epoch Game render
+ submission exists.
+- Desktop `Esc` is a host/SystemOS Home request; physical `Home` may alias it.
+- Home/SystemOS is not a guest pad button and is not userland input.
+- Background execution and general multitasking are explicitly excluded.
+
+## Impactos
+
+- **Spec:** runtime lifecycle, firmware/Hub, input, and render ownership specs
+ must document foreground ownership, pause/suspend semantics, Home key mapping,
+ and stale frame invalidation.
+- **Runtime / SystemOS:** SystemOS needs explicit foreground owner, Hub root,
+ Shell foreground, Game paused, and Game suspended state.
+- **VM:** VM execution must support pause/resume lifecycle delivery and OS-owned
+ suspension of ticks.
+- **Firmware:** firmware should observe macro transitions such as GameRunning,
+ Hub/Home, Shell foreground, pause request, and resume request without owning
+ every internal OS detail.
+- **Host:** host must route desktop `Esc` and optional physical `Home` to a
+ SystemOS Home request instead of guest pad input.
+- **Input:** Game input must be drained or barriered during pause/resume and
+ Home/SystemOS must stay outside the guest-visible pad ABI.
+- **Audio:** v1 audio follows Game pause/suspend and does not continue as
+ independent background audio.
+- **Renderer:** render publication must reject stale submissions after ownership
+ epoch changes and keep previous foreground visible until the resumed Game
+ publishes a valid current-epoch frame.
+- **Tests:** coverage must prove pause budget behavior, non-foreground VM
+ non-execution, input clearing, host Home routing, Shell return-to-Hub, and
+ stale render rejection.
+
+## Alternativas Descartadas
+
+- **Terminate Game when entering Shell:** rejected because it makes
+ `Game -> Shell -> Game` a reload rather than a pause/resume flow.
+- **Real background execution now:** rejected because it pulls in scheduler,
+ budget, energy, audio, input, IO, memory, and persistence policy beyond v1.
+- **Multiple resident Games:** rejected for v1 because Game-to-Game switching is
+ owned by `DSC-0043 / AGD-0044`.
+- **Expose Home as guest input:** rejected because Home changes system
+ foreground authority and must not be handled as ordinary game input.
+- **Return directly from Shell app to Game in v1:** rejected to keep Hub as the
+ deterministic root/back-stack owner.
+
+## Referencias
+
+- Source agenda: `AGD-0041`
+- Runtime mode separation: `DSC-0031`
+- SystemOS lifecycle authority: `DSC-0032`
+- Shell task/window lifecycle: `DSC-0035`
+- Hub UI direction: `DSC-0036`
+- Render ownership and stale submission handling: `DSC-0040`
+- Future Game A -> Home -> Game B switching: `DSC-0043 / AGD-0044`
+
+## Propagacao Necessaria
+
+- Update canonical runtime specs for foreground ownership and pause/suspend.
+- Specify desktop Home request mapping in host/input documentation.
+- Add plan(s) for SystemOS foreground stack state and Game pause/suspend.
+- Add plan(s) for VM lifecycle event delivery and forced suspension budget.
+- Add plan(s) for host `Esc`/`Home` routing outside guest pad input.
+- Add plan(s) for render epoch integration during Game/Shell transitions.
+- Add tests covering lifecycle, input, host routing, and render publication
+ invariants.
+
+## Revision Log
+
+- 2026-07-03: Initial decision from `AGD-0041`.
diff --git a/discussion/workflow/plans/PLN-0129-remove-userland-run-cart-abi-surface.md b/discussion/workflow/plans/PLN-0129-remove-userland-run-cart-abi-surface.md
deleted file mode 100644
index 52c071ae..00000000
--- a/discussion/workflow/plans/PLN-0129-remove-userland-run-cart-abi-surface.md
+++ /dev/null
@@ -1,90 +0,0 @@
----
-id: PLN-0129
-ticket: system-run-cart
-title: Remove Userland Run Cart ABI Surface
-status: done
-created: 2026-07-03
-ref_decisions: [DEC-0035]
-tags: []
----
-
-## Briefing
-
-`DEC-0035` removes `system.run_cart` from the userland guest ABI. This plan
-covers the public ABI, syscall registry/declaration surface, generated metadata,
-and documentation/spec propagation. It does not change runtime dispatch behavior
-or direct boot tests; those are covered by `PLN-0130` and `PLN-0131`.
-
-## Objective
-
-Remove `system.run_cart` from every app-callable/userland ABI surface while
-preserving non-guest direct boot entrypoints.
-
-## Dependencies
-
-- Source decision: `DEC-0035`.
-- Must stay scoped away from `AGD-0041` and `AGD-0044`.
-- Coordinate with `PLN-0130` so runtime dispatch does not retain a callable
- success path after the declaration is removed.
-
-## Scope
-
-- Remove or retire `Syscall::SystemRunCart` from userland-visible syscall
- declarations in `crates/console/prometeu-hal/src/syscalls.rs`.
-- Remove the `system.run_cart` registry entry from
- `crates/console/prometeu-hal/src/syscalls/domains/system.rs` and
- `crates/console/prometeu-hal/src/syscalls/registry.rs`, unless implementation
- discovers an internal-only registry distinct from guest ABI.
-- Remove generated/static bytecode or VM-facing declarations that expose
- `system.run_cart`, including known references in
- `crates/console/prometeu-bytecode/src/model.rs` and
- `crates/console/prometeu-vm/src/virtual_machine.rs` if they include it.
-- Update docs/specs that mention `system.run_cart` as app-callable.
-- Update `AGD-0004` references only if they become factually misleading after
- removal; do not close or reinterpret that agenda.
-
-## Non-Goals
-
-- Do not implement `Home -> another Game`.
-- Do not add a replacement app navigation syscall.
-- Do not implement `.pmc`.
-- Do not change direct host/CLI/debug boot behavior.
-- Do not add compatibility stubs for obsolete guest code.
-
-## Execution Method
-
-1. Search for `SystemRunCart`, `run_cart`, and `"system", "run_cart"` across
- `crates/`, `docs/`, and `discussion/`.
-2. Remove `system.run_cart` from userland syscall domain declarations and
- lookup/name registries.
-3. Remove generated/static guest-facing metadata entries that advertise
- `system.run_cart`.
-4. Update docs/specs to state that cartridges are booted by host/system paths,
- not by guest syscall.
-5. Compile the workspace or targeted crates to find stale references.
-
-## Acceptance Criteria
-
-- No userland ABI declaration advertises `system.run_cart`.
-- No generated guest metadata exposes `run_cart` as callable.
-- Documentation/spec text no longer describes app-callable cartridge boot.
-- Any retained code path is clearly internal-only and is not reachable through
- guest syscall lookup.
-
-## Tests
-
-- Add or update syscall registry tests to assert `system.run_cart` is absent
- from the public/userland registry.
-- Run targeted tests for `prometeu-hal`, `prometeu-bytecode`, and
- `prometeu-vm` if available.
-- Run repository validation commands used for syscall declaration consistency.
-
-## Affected Artifacts
-
-- `crates/console/prometeu-hal/src/syscalls.rs`
-- `crates/console/prometeu-hal/src/syscalls/domains/system.rs`
-- `crates/console/prometeu-hal/src/syscalls/registry.rs`
-- `crates/console/prometeu-bytecode/src/model.rs`
-- `crates/console/prometeu-vm/src/virtual_machine.rs`
-- `docs/specs/runtime/`
-- `discussion/workflow/agendas/AGD-0004-system-fault-semantics-and-control-surface.md`
diff --git a/discussion/workflow/plans/PLN-0130-remove-runtime-run-cart-stub-dispatch.md b/discussion/workflow/plans/PLN-0130-remove-runtime-run-cart-stub-dispatch.md
deleted file mode 100644
index 71be6a70..00000000
--- a/discussion/workflow/plans/PLN-0130-remove-runtime-run-cart-stub-dispatch.md
+++ /dev/null
@@ -1,79 +0,0 @@
----
-id: PLN-0130
-ticket: system-run-cart
-title: Remove Runtime Run Cart Stub Dispatch
-status: done
-created: 2026-07-03
-ref_decisions: [DEC-0035]
-tags: []
----
-
-## Briefing
-
-`DEC-0035` forbids a callable userland `system.run_cart` stub. This plan covers
-runtime and VM dispatch cleanup so obsolete calls cannot silently succeed.
-Public ABI removal is handled by `PLN-0129`; direct boot preservation is handled
-by `PLN-0131`.
-
-## Objective
-
-Remove the runtime no-op dispatch path for `SystemRunCart` and ensure stale or
-obsolete userland attempts fail explicitly rather than returning success.
-
-## Dependencies
-
-- Source decision: `DEC-0035`.
-- Depends on the ABI direction in `PLN-0129`, but can be implemented in the same
- PR if the public enum/registry removal and dispatch cleanup move together.
-
-## Scope
-
-- Remove the `Syscall::SystemRunCart => return Ok(())` path from
- `crates/console/prometeu-system/src/services/vm_runtime/dispatch.rs`.
-- Update any match arms made unreachable or obsolete by removing
- `SystemRunCart`.
-- Ensure stale numeric syscall ids or stale bytecode declarations fail with the
- repository's existing unknown/invalid syscall behavior.
-- Add negative coverage for userland attempts to invoke the removed operation,
- using the closest existing VM runtime syscall tests.
-
-## Non-Goals
-
-- Do not implement a replacement navigation operation.
-- Do not implement the `Home -> another Game` orchestrator.
-- Do not alter direct host/CLI/debug cartridge boot paths.
-- Do not change `system.has_cart` behavior unless required by compile fallout.
-
-## Execution Method
-
-1. Inspect `dispatch.rs` for all `SystemRunCart` match arms.
-2. Remove the no-op success path and any unreachable arms tied only to
- `SystemRunCart`.
-3. If the public enum variant is removed by `PLN-0129`, update exhaustiveness
- and registry mapping accordingly.
-4. Add or update VM runtime tests that demonstrate `system.run_cart` is not
- callable from guest/userland.
-5. Run targeted runtime tests and compile checks.
-
-## Acceptance Criteria
-
-- There is no runtime path where a guest `system.run_cart` call returns `Ok(())`.
-- Stale/obsolete attempts fail explicitly through existing invalid syscall or
- declaration validation behavior.
-- `system.has_cart` and unrelated system syscalls keep their current behavior.
-- Runtime dispatch remains exhaustive and clear after removing `SystemRunCart`.
-
-## Tests
-
-- Add a negative test in `crates/console/prometeu-system/src/services/vm_runtime`
- for stale userland `run_cart` attempts, if the test harness can express it.
-- Run `cargo test` for `prometeu-system` and any impacted syscall crates.
-- Run a workspace compile/test command if targeted tests reveal cross-crate enum
- fallout.
-
-## Affected Artifacts
-
-- `crates/console/prometeu-system/src/services/vm_runtime/dispatch.rs`
-- `crates/console/prometeu-system/src/services/vm_runtime/tests.rs`
-- `crates/console/prometeu-hal/src/syscalls.rs`
-- `crates/console/prometeu-hal/src/syscalls/registry.rs`
diff --git a/discussion/workflow/plans/PLN-0131-preserve-direct-cartridge-boot-coverage.md b/discussion/workflow/plans/PLN-0131-preserve-direct-cartridge-boot-coverage.md
deleted file mode 100644
index 75660a8c..00000000
--- a/discussion/workflow/plans/PLN-0131-preserve-direct-cartridge-boot-coverage.md
+++ /dev/null
@@ -1,83 +0,0 @@
----
-id: PLN-0131
-ticket: system-run-cart
-title: Preserve Direct Cartridge Boot Coverage
-status: done
-created: 2026-07-03
-ref_decisions: [DEC-0035]
-tags: []
----
-
-## Briefing
-
-`DEC-0035` removes userland `system.run_cart`, but direct cartridge boot remains
-mandatory for development, debugging, automated tests, and future single-game
-launch scenarios. This plan protects that path while the guest syscall is
-removed.
-
-## Objective
-
-Preserve and test host/CLI/debug direct cartridge boot without relying on a
-guest syscall.
-
-## Dependencies
-
-- Source decision: `DEC-0035`.
-- Can be implemented after or alongside `PLN-0129` and `PLN-0130`.
-- Must not depend on `.pmc`, app catalog, launcher UX, `AGD-0041`, or
- `AGD-0044`.
-
-## Scope
-
-- Identify direct boot entrypoints in `crates/tools/prometeu-cli/src/main.rs`,
- `crates/host/prometeu-host-desktop-winit/src/lib.rs`,
- `crates/host/prometeu-host-desktop-winit/src/debugger.rs`, and firmware
- cartridge loading code.
-- Add or preserve tests showing a cartridge can be loaded directly into
- firmware/runtime from host or CLI paths.
-- Ensure these paths do not call or require `system.run_cart`.
-- Document the distinction between direct boot and guest navigation where
- runtime specs describe boot behavior.
-
-## Non-Goals
-
-- Do not implement `Home -> another Game`.
-- Do not add app-callable navigation.
-- Do not require `.pmc`.
-- Do not redesign cartridge loader internals beyond what is required to keep
- direct boot working.
-
-## Execution Method
-
-1. Trace the CLI/debug direct boot path from cartridge path argument through
- loader, firmware `load_cartridge`, and runtime initialization.
-2. Add regression tests at the lowest practical layer proving direct boot still
- reaches `GameRunning` for a valid game cartridge.
-3. Add a guard or assertion that direct boot does not depend on `system.run_cart`
- metadata.
-4. Update docs/specs to describe direct boot as host/system-controlled.
-5. Run targeted CLI/firmware/host tests.
-
-## Acceptance Criteria
-
-- A valid game cartridge can still boot directly from host/CLI/debug paths.
-- Direct boot does not depend on `system.run_cart` being in the guest syscall
- registry.
-- Existing debugger/handshake metadata that reports cartridge info still works.
-- The direct boot behavior is documented as host/system entry, not guest ABI.
-
-## Tests
-
-- Add or preserve firmware tests around `load_cartridge` and `GameRunning`.
-- Add or preserve host/CLI tests for cartridge path boot when practical.
-- Run `cargo test` for `prometeu-firmware`, `prometeu-host-desktop-winit`, and
- `prometeu-cli` where available.
-
-## Affected Artifacts
-
-- `crates/tools/prometeu-cli/src/main.rs`
-- `crates/host/prometeu-host-desktop-winit/src/lib.rs`
-- `crates/host/prometeu-host-desktop-winit/src/debugger.rs`
-- `crates/console/prometeu-firmware/src/firmware/firmware.rs`
-- `crates/console/prometeu-firmware/src/firmware/firmware_step_load_cartridge.rs`
-- `docs/specs/runtime/`
diff --git a/discussion/workflow/plans/PLN-0132-specify-games-root-home-launch-contract.md b/discussion/workflow/plans/PLN-0132-specify-games-root-home-launch-contract.md
deleted file mode 100644
index 7bd714c1..00000000
--- a/discussion/workflow/plans/PLN-0132-specify-games-root-home-launch-contract.md
+++ /dev/null
@@ -1,103 +0,0 @@
----
-id: PLN-0132
-ticket: system-run-cart
-title: Specify Games Root Home Launch Contract
-status: done
-created: 2026-07-03
-ref_decisions: [DEC-0036]
-tags: []
----
-
-## Briefing
-
-`DEC-0036` establishes a new system-owned game library launch path:
-the host receives `--games-root `, SystemOS/Home lists valid Game
-directory cartridges from that root, and selecting one starts the cartridge
-through firmware loading rather than a guest syscall.
-
-This plan updates the normative specs before code is changed.
-
-## Objective
-
-Document the v1 games-root and Home launch contract in the canonical runtime
-specs so implementation plans cannot drift back into userland `run_cart` or
-general app-library semantics.
-
-## Dependencies
-
-- Source decision: `DEC-0036`.
-- Prior decision: `DEC-0035`, which removed userland `system.run_cart` and
- preserved direct `--run` boot.
-- This plan must be completed before `PLN-0133`, `PLN-0134`, and `PLN-0135`.
-
-## Scope
-
-- Update the runtime specs to define `--games-root ` as the v1 local games
- library root.
-- Specify that discovery scans only immediate child directories.
-- Specify that v1 library discovery includes only valid directory cartridges
- with `app_mode: Game`.
-- Specify that `.pmc`, recursive discovery, Shell/System apps, marketplace
- metadata, rich presentation, search, and non-game apps are out of scope.
-- Specify the internal library entry contract: loaded manifest data, `title`,
- `app_id`, `app_version`, internal cartridge path, and discovery metadata.
-- Specify that Home v1 may display only `title`, `app_id`, and `app_version`.
-- Specify that selecting a Home game emits a system-owned launch request that
- transitions through firmware/SystemOS into `LoadCartridge`.
-- Specify that invalid candidates are logged and omitted.
-- Specify that launch failure remains or returns to Home and logs the failure.
-- Reaffirm that direct `--run ` boot remains independent and unchanged.
-
-## Non-Goals
-
-- No Rust implementation.
-- No Home UI changes.
-- No `.pmc` discovery or packaged-cartridge spec changes.
-- No recursive library layout.
-- No return-to-Home behavior for a running Game.
-- No Game A -> Home -> Game B orchestration.
-- No guest syscall or userland ABI addition.
-
-## Execution Method
-
-1. Update [docs/specs/runtime/14-boot-profiles.md](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/docs/specs/runtime/14-boot-profiles.md) with:
- - direct `--run` boot remaining a single-cartridge boot profile;
- - `--games-root ` as a SystemOS/Home library profile;
- - the distinction between direct boot, Home launch, and future game-switch
- orchestration.
-2. Update [docs/specs/runtime/12-firmware-pos-and-prometeuhub.md](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/docs/specs/runtime/12-firmware-pos-and-prometeuhub.md) with:
- - Home's responsibility to display the local games library;
- - the system-owned launch action boundary;
- - failure handling that leaves the machine in Home and records an error.
-3. Update [docs/specs/runtime/13-cartridge.md](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/docs/specs/runtime/13-cartridge.md) with:
- - directory-cartridge discovery requirements for library candidates;
- - Game-only filtering by manifest `app_mode`;
- - invalid candidate omission and diagnostics.
-4. Update [docs/specs/runtime/16-host-abi-and-syscalls.md](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/docs/specs/runtime/16-host-abi-and-syscalls.md) only if needed to reinforce that no guest syscall owns cartridge launch.
-5. Keep all spec text in English.
-
-## Acceptance Criteria
-
-- The specs define `--games-root ` and do not describe it as a generic app
- root.
-- The specs state that v1 scans immediate child directories only.
-- The specs state that only valid Game directory cartridges enter the Home list.
-- The specs state that Home launch is system-owned and enters `LoadCartridge`.
-- The specs preserve `--run ` as a separate direct boot path.
-- The specs explicitly exclude `.pmc`, recursive discovery, return-to-Home, and
- game-switch orchestration from this implementation slice.
-- No spec reintroduces userland `run_cart`.
-
-## Tests
-
-- Run `discussion validate`.
-- Run targeted text checks for `--games-root`, `LoadCartridge`, and absence of
- `system.run_cart` as an active public launch mechanism in edited specs.
-
-## Affected Artifacts
-
-- `docs/specs/runtime/12-firmware-pos-and-prometeuhub.md`
-- `docs/specs/runtime/13-cartridge.md`
-- `docs/specs/runtime/14-boot-profiles.md`
-- `docs/specs/runtime/16-host-abi-and-syscalls.md`
-- `discussion/workflow/plans/PLN-0132-specify-games-root-home-launch-contract.md`
diff --git a/discussion/workflow/plans/PLN-0133-implement-games-root-library-discovery.md b/discussion/workflow/plans/PLN-0133-implement-games-root-library-discovery.md
deleted file mode 100644
index 65bc21f2..00000000
--- a/discussion/workflow/plans/PLN-0133-implement-games-root-library-discovery.md
+++ /dev/null
@@ -1,118 +0,0 @@
----
-id: PLN-0133
-ticket: system-run-cart
-title: Implement Games Root Library Discovery
-status: done
-created: 2026-07-03
-ref_decisions: [DEC-0036]
-tags: []
----
-
-## Briefing
-
-`DEC-0036` requires a host-provided games root and an expandable internal
-library model before Home can render or launch games. This plan implements the
-library discovery and host plumbing only; UI launch wiring is handled by
-`PLN-0134`.
-
-## Objective
-
-Add a tested games-root discovery model that scans immediate child directory
-cartridges, filters to valid Game manifests, records diagnostics for invalid
-candidates, and carries enough metadata for Home rendering and later launch.
-
-## Dependencies
-
-- Source decision: `DEC-0036`.
-- `PLN-0132` should be completed first so code follows the documented contract.
-- Existing cartridge manifest and directory loader behavior in the console
- crates.
-- Existing host CLI and `HostRunner` boot setup.
-
-## Scope
-
-- Add `--games-root ` to the desktop host CLI.
-- Pass the optional games root into the host runner / firmware initialization
- path without changing direct `--run` or `--debug` boot behavior.
-- Add a SystemOS-owned games library model for directory cartridge discovery.
-- Scan only immediate child directories of the root.
-- Read and retain manifest data for each valid candidate.
-- Include only candidates whose manifest declares `app_mode: Game`.
-- Retain internal cartridge path and operational discovery metadata on each
- entry.
-- Emit diagnostics for invalid, unreadable, or non-Game candidates and omit
- them from the returned entries.
-- Keep discovery independent from full cartridge launch: discovery reads
- metadata; launch still uses the existing loader in `PLN-0134`.
-
-## Non-Goals
-
-- No Home list rendering.
-- No click handling or `LoadCartridge` transition.
-- No `.pmc` discovery.
-- No recursive scan.
-- No Shell/System app catalog.
-- No marketplace metadata, icons, search, sorting UI, or polished errors.
-- No new guest syscall.
-
-## Execution Method
-
-1. Introduce a library/discovery module in the SystemOS side, preferably under
- `crates/console/prometeu-system/src/services/` unless the existing module
- layout has a more local owner.
-2. Define an internal entry type with at least:
- - loaded cartridge manifest data;
- - `title`;
- - `app_id`;
- - `app_version`;
- - internal cartridge path;
- - discovery metadata, using `SystemTime` or another explicit discovery
- marker.
-3. Define discovery diagnostics that can be logged by the caller and asserted in
- tests.
-4. Implement a scanner that:
- - accepts an optional root path;
- - returns an empty library when no root is configured;
- - iterates only immediate child directories;
- - parses `manifest.json` using structured manifest types, not ad hoc string
- matching;
- - filters to `app_mode: Game`;
- - sorts entries deterministically for stable Home presentation and tests.
-5. Add `--games-root ` to
- [crates/host/prometeu-host-desktop-winit/src/lib.rs](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/crates/host/prometeu-host-desktop-winit/src/lib.rs)
- and pass the path into
- [crates/host/prometeu-host-desktop-winit/src/runner.rs](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/crates/host/prometeu-host-desktop-winit/src/runner.rs).
-6. Store or expose the discovered library to firmware/SystemOS in a way that
- `PLN-0134` can consume without re-scanning inside the Home click path.
-7. Add focused unit tests using temporary cartridge roots with:
- - one valid Game directory cartridge;
- - one valid non-Game cartridge;
- - one invalid directory;
- - one nested directory that must not be discovered.
-
-## Acceptance Criteria
-
-- `--games-root ` is accepted by the desktop host CLI.
-- Absence of `--games-root` leaves existing Hub boot behavior unchanged.
-- Direct `--run ` and `--debug ` behavior remains unchanged.
-- Discovery returns only immediate valid Game directory cartridges.
-- Each library entry retains manifest data, path, title, app id, app version,
- and discovery metadata.
-- Invalid candidates are represented in diagnostics and excluded from entries.
-- Discovery does not fully load or boot cartridge programs.
-
-## Tests
-
-- Add and run focused games-library discovery tests in the owning console crate.
-- Run `cargo test -p prometeu-system` if the library lives in
- `prometeu-system`.
-- Run `cargo test -p prometeu-host-desktop-winit` for CLI/runner plumbing.
-- Run `discussion validate`.
-
-## Affected Artifacts
-
-- `crates/console/prometeu-system/src/services/`
-- `crates/console/prometeu-system/src/lib.rs` or module exports as needed
-- `crates/host/prometeu-host-desktop-winit/src/lib.rs`
-- `crates/host/prometeu-host-desktop-winit/src/runner.rs`
-- `discussion/workflow/plans/PLN-0133-implement-games-root-library-discovery.md`
diff --git a/discussion/workflow/plans/PLN-0134-wire-home-game-list-launch-flow.md b/discussion/workflow/plans/PLN-0134-wire-home-game-list-launch-flow.md
deleted file mode 100644
index 001a2bf0..00000000
--- a/discussion/workflow/plans/PLN-0134-wire-home-game-list-launch-flow.md
+++ /dev/null
@@ -1,104 +0,0 @@
----
-id: PLN-0134
-ticket: system-run-cart
-title: Wire Home Game List Launch Flow
-status: done
-created: 2026-07-03
-ref_decisions: [DEC-0036]
-tags: []
----
-
-## Briefing
-
-After `PLN-0133`, SystemOS can discover a local Game library but Home still
-does not present or launch those entries. This plan wires the discovered
-library into Prometeu Hub/Home and routes a selected game to firmware
-`LoadCartridge`.
-
-## Objective
-
-Make Home display a minimal clickable games list and launch the selected Game
-through a system-owned firmware/SystemOS path, without reintroducing userland
-`run_cart`.
-
-## Dependencies
-
-- Source decision: `DEC-0036`.
-- `PLN-0132` for documented contract.
-- `PLN-0133` for `--games-root` plumbing and the internal library entry model.
-- Existing Prometeu Hub Home profile and firmware state transitions.
-
-## Scope
-
-- Provide the discovered games library to Prometeu Hub/Home.
-- Render a minimal Home list showing `title`, `app_id`, and `app_version`.
-- Add Home hit-testing/click handling for game entries.
-- Extend the system profile action model with a system-owned game launch action.
-- Handle that action in firmware/SystemOS by loading the selected cartridge via
- the existing cartridge loader and entering `LoadCartridge`.
-- On load failure, log/record the error and keep or return the machine to Home.
-- Preserve existing native shell launch behavior.
-
-## Non-Goals
-
-- No polished launcher UI.
-- No icons, screenshots, search, filtering, or marketplace metadata.
-- No return-to-Home while a Game is running.
-- No Game A -> Home -> Game B foreground orchestration.
-- No `.pmc` launch support.
-- No guest syscall.
-- No direct-boot behavior changes.
-
-## Execution Method
-
-1. Extend the SystemOS/Hub action type currently represented by
- `SystemProfileAction::LaunchNativeShell` with a game-launch action that
- carries a stable reference to the selected library entry or cartridge path.
-2. Update the Prometeu Hub state in
- [crates/console/prometeu-system/src/programs/prometeu_hub.rs](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/crates/console/prometeu-system/src/programs/prometeu_hub.rs)
- or its local modules to accept the discovered game entries.
-3. Render the Home games list with stable dimensions and simple clickable rows.
- Rows must display only `title`, `app_id`, and `app_version` for v1.
-4. Add hit-testing so selecting a row emits the game-launch action immediately.
-5. Update
- [crates/console/prometeu-firmware/src/firmware/steps/firmware_step_hub_home.rs](/Users/niltonconstantino/personal/workspace.personal/intrepid/prometeu/runtime/crates/console/prometeu-firmware/src/firmware/steps/firmware_step_hub_home.rs)
- to consume the new action.
-6. In the firmware action handler:
- - call the existing cartridge loader for the selected path;
- - on success, return `FirmwareState::LoadCartridge(...)`;
- - on failure, log/record the error and remain in the Home path.
-7. Ensure shell launch still works exactly as before.
-8. Add unit or integration tests for:
- - Home list presentation data;
- - click-to-action emission;
- - firmware action handling success;
- - firmware action handling failure.
-
-## Acceptance Criteria
-
-- Starting the host with `--games-root ` exposes valid Game entries in
- Home.
-- The Home list displays `title`, `app_id`, and `app_version`.
-- Clicking a listed Game routes through a system action and enters
- `LoadCartridge`.
-- The launch path does not use a guest syscall and does not mention
- `system.run_cart`.
-- Invalid or failing launch paths remain in Home and record an error.
-- Existing native shell Home actions continue to work.
-- Direct `--run` remains separate and unchanged.
-
-## Tests
-
-- Run `cargo test -p prometeu-system` for Hub action and presentation behavior.
-- Run `cargo test -p prometeu-firmware` for firmware transition behavior.
-- Run `cargo test -p prometeu-host-desktop-winit` if runner integration changes.
-- Run `discussion validate`.
-
-## Affected Artifacts
-
-- `crates/console/prometeu-system/src/programs/prometeu_hub.rs`
-- `crates/console/prometeu-system/src/services/`
-- `crates/console/prometeu-firmware/src/firmware/steps/firmware_step_hub_home.rs`
-- `crates/console/prometeu-firmware/src/firmware/firmware.rs`
-- `crates/host/prometeu-host-desktop-winit/src/runner.rs`
-- `discussion/workflow/plans/PLN-0134-wire-home-game-list-launch-flow.md`
diff --git a/discussion/workflow/plans/PLN-0135-validate-games-root-launch-end-to-end.md b/discussion/workflow/plans/PLN-0135-validate-games-root-launch-end-to-end.md
deleted file mode 100644
index 95721ff1..00000000
--- a/discussion/workflow/plans/PLN-0135-validate-games-root-launch-end-to-end.md
+++ /dev/null
@@ -1,99 +0,0 @@
----
-id: PLN-0135
-ticket: system-run-cart
-title: Validate Games Root Launch End To End
-status: done
-created: 2026-07-03
-ref_decisions: [DEC-0036]
-tags: []
----
-
-## Briefing
-
-`PLN-0132` through `PLN-0134` specify, discover, display, and launch games
-from a local games root. This plan closes the slice by adding end-to-end
-validation evidence and manual smoke instructions for the product behavior the
-user wants: point the SO at a directory, click a listed game, and boot it.
-
-## Objective
-
-Prove the complete `--games-root -> Home list -> click -> LoadCartridge ->
-GameRunning` path while preserving direct `--run` boot and the absence of
-userland `run_cart`.
-
-## Dependencies
-
-- Source decision: `DEC-0036`.
-- `PLN-0132`, `PLN-0133`, and `PLN-0134` must be complete.
-- Existing test cartridge fixtures, especially `test-cartridges/stress-console`.
-
-## Scope
-
-- Add automated integration coverage for the full games-root Home launch path
- where the existing host/firmware test seams allow it.
-- Add or document a minimal local games-root fixture using existing directory
- cartridges.
-- Validate invalid-candidate omission at the end-to-end boundary.
-- Validate direct `--run` still works after games-root wiring.
-- Capture manual smoke-test commands for release-mode functional verification.
-
-## Non-Goals
-
-- No new product UI polish.
-- No screenshot automation unless the existing test harness already supports it
- cleanly.
-- No return-to-Home after a running Game.
-- No Game A -> Home -> Game B orchestration.
-- No `.pmc` validation.
-- No broad performance tuning beyond confirming release-mode smoke behavior.
-
-## Execution Method
-
-1. Add an integration-style firmware or host test that constructs a games root
- with a valid Game directory cartridge and boots to Hub/Home with that root.
-2. Drive the Home selection path through the same action path used by user
- input, not by calling the cartridge loader directly.
-3. Assert that the machine reaches `LoadCartridge` or `GameRunning`, depending
- on the most stable observable state available in the test harness.
-4. Add a negative case with an invalid candidate and assert it is omitted or
- reported as a diagnostic without appearing in Home.
-5. Add a regression assertion that no public guest syscall named
- `system.run_cart` is required by this path.
-6. Re-run direct boot tests or add a small regression test proving
- `--run test-cartridges/stress-console` remains independent from
- `--games-root`.
-7. Record manual smoke commands in the relevant spec or developer-facing doc:
- - `cargo run --release -p prometeu-host-desktop-winit -- --games-root test-cartridges`
- - `cargo run --release -p prometeu-host-desktop-winit -- --run test-cartridges/stress-console`
-
-## Acceptance Criteria
-
-- Automated tests cover a valid games-root Home launch path.
-- Automated tests cover invalid candidate omission or diagnostics at the
- end-to-end boundary.
-- Automated or documented validation proves direct `--run` still works.
-- Manual smoke instructions use release mode for realistic interactive speed.
-- Validation evidence shows no guest syscall participates in launch.
-- `discussion validate` passes.
-
-## Tests
-
-- Run `cargo test -p prometeu-system`.
-- Run `cargo test -p prometeu-firmware`.
-- Run `cargo test -p prometeu-host-desktop-winit`.
-- Run `cargo test -p prometeu-hal syscalls` to keep the removed syscall surface
- guarded.
-- Manually smoke test:
- `cargo run --release -p prometeu-host-desktop-winit -- --games-root test-cartridges`.
-- Manually smoke test:
- `cargo run --release -p prometeu-host-desktop-winit -- --run test-cartridges/stress-console`.
-- Run `discussion validate`.
-
-## Affected Artifacts
-
-- `crates/console/prometeu-system/`
-- `crates/console/prometeu-firmware/`
-- `crates/host/prometeu-host-desktop-winit/`
-- `crates/console/prometeu-hal/src/syscalls/tests.rs`
-- Runtime specs or developer docs containing smoke commands
-- `discussion/workflow/plans/PLN-0135-validate-games-root-launch-end-to-end.md`
diff --git a/discussion/workflow/plans/PLN-0136-route-desktop-home-key-outside-guest-input.md b/discussion/workflow/plans/PLN-0136-route-desktop-home-key-outside-guest-input.md
new file mode 100644
index 00000000..7117ec6e
--- /dev/null
+++ b/discussion/workflow/plans/PLN-0136-route-desktop-home-key-outside-guest-input.md
@@ -0,0 +1,96 @@
+---
+id: PLN-0136
+ticket: foreground-stack-game-pause-shell-vm-backed
+title: Route Desktop Home Key Outside Guest Input
+status: open
+created: 2026-07-03
+ref_decisions: [DEC-0037]
+tags: [host, input, systemos, keyboard, lifecycle]
+---
+
+## Briefing
+
+`DEC-0037` makes desktop `Esc` the primary Home/SystemOS request and allows the
+physical `Home` key as an alias. This request must be intercepted by the
+host/SystemOS and must not appear as a guest pad button or input intrinsic.
+
+This plan adds the host input route for the Home request without changing the
+guest-visible pad surface.
+
+## Decisions of Origin
+
+- `DEC-0037` - Foreground Stack and Game Pause Contract.
+
+## Target
+
+Route desktop `Esc` and optional physical `Home` key to a SystemOS Home request
+outside `InputSignals`.
+
+## Scope
+
+- Extend `crates/host/prometeu-host-desktop-winit/src/input.rs` or a nearby
+ host input module with a host/system control signal separate from
+ `prometeu_hal::InputSignals`.
+- Map `KeyCode::Escape` to Home/SystemOS request.
+- Map `KeyCode::Home` as an alias.
+- Ensure neither key mutates `start_signal`, `select_signal`, or any pad field.
+- Route the request through `crates/host/prometeu-host-desktop-winit/src/runner.rs`
+ into firmware/SystemOS.
+- Add tests proving `Esc` and `Home` do not affect guest pad state.
+
+## Out of Scope
+
+- No pause/resume lifecycle implementation.
+- No render ownership gating.
+- No guest-visible Home button.
+- No gamepad hardware Home mapping unless a future plan defines controller
+ system controls separately.
+
+## Execution Plan
+
+1. Define host control state.
+ Add a small host-only type such as `HostSystemControls` with a
+ `home_requested` edge or event. Store it in `HostInputHandler` or in the
+ runner next to the existing input handler.
+
+2. Update keyboard handling.
+ In `HostInputHandler::handle_event`, recognize `KeyCode::Escape` and
+ `KeyCode::Home` on press. Set the host control event and return without
+ modifying `InputSignals`.
+
+3. Preserve pad mapping.
+ Keep existing pad mappings unchanged:
+ arrows, `A/D/W/S`, `Q/E`, `Z`, and Shift. Do not reuse `Start` or `Select`
+ for Home.
+
+4. Route to firmware/SystemOS.
+ In `crates/host/prometeu-host-desktop-winit/src/runner.rs`, consume the
+ host Home event before or during `about_to_wait` and call the firmware or
+ SystemOS method introduced by `PLN-0137` / `PLN-0140`.
+
+5. Add tests.
+ Add host input tests for `Esc`, physical `Home`, and existing pad mappings.
+ Tests must prove Home produces a system event and no guest pad mutation.
+
+## Acceptance Criteria
+
+- Pressing desktop `Esc` emits a Home/SystemOS host control event.
+- Pressing physical `Home` emits the same event.
+- Neither key affects `InputSignals`.
+- Existing guest pad keyboard mappings still work.
+- The runner consumes the Home request as a system action.
+- The implementation does not add a guest syscall, intrinsic, or pad button.
+
+## Tests / Validation
+
+- Add unit tests in `prometeu-host-desktop-winit` for host input mapping.
+- Run `cargo test -p prometeu-host-desktop-winit input`.
+- Run `cargo test -p prometeu-hal input` if pad signal behavior changes.
+- Run `discussion validate`.
+
+## Risks
+
+- `Esc` may conflict with debugger or window-close expectations. Keep debugger
+ start handling on `D` unchanged and do not map `Esc` to process exit.
+- Physical `Home` is not available on every keyboard, so it must remain an
+ alias rather than the primary portable mapping.
diff --git a/discussion/workflow/plans/PLN-0137-implement-systemos-foreground-stack-state.md b/discussion/workflow/plans/PLN-0137-implement-systemos-foreground-stack-state.md
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--- /dev/null
+++ b/discussion/workflow/plans/PLN-0137-implement-systemos-foreground-stack-state.md
@@ -0,0 +1,116 @@
+---
+id: PLN-0137
+ticket: foreground-stack-game-pause-shell-vm-backed
+title: Implement SystemOS Foreground Stack State
+status: open
+created: 2026-07-03
+ref_decisions: [DEC-0037]
+tags: [runtime, os, lifecycle, foreground, shell, game]
+---
+
+## Briefing
+
+`DEC-0037` requires SystemOS to own foreground authority. The system must know
+which owner is foreground, keep Hub/Home as root, allow only one resident Game,
+allow only one foreground Shell, and return from VM-backed Shell apps to Hub in
+v1.
+
+This plan implements the SystemOS state model only. It does not yet deliver
+Game pause/resume events, host keyboard routing, or render/audio/input boundary
+changes.
+
+## Decisions of Origin
+
+- `DEC-0037` - Foreground Stack and Game Pause Contract.
+
+## Target
+
+Add an explicit SystemOS foreground stack model that can represent Hub, a
+foreground Shell task, and a paused/suspended resident Game.
+
+## Scope
+
+- Add or extend SystemOS-owned foreground state under
+ `crates/console/prometeu-system/src/os/` or
+ `crates/console/prometeu-system/src/services/`.
+- Represent v1 foreground owners:
+ - Hub/Home root;
+ - Shell task foreground;
+ - Game foreground;
+ - Game paused/suspended resident.
+- Enforce at most one resident Game and at most one foreground Shell.
+- Keep Hub as root/back-stack controller.
+- Ensure Shell close returns to Hub/Home in v1.
+- Expose focused queries through existing or new facades, likely
+ `crates/console/prometeu-system/src/os/facades/lifecycle.rs` and
+ `crates/console/prometeu-system/src/os/facades/sessions.rs`.
+
+## Out of Scope
+
+- No VM pause/resume event delivery.
+- No host `Esc`/`Home` keyboard mapping.
+- No render epoch implementation.
+- No Game-to-Game switching.
+- No background execution.
+- No memory eviction for the resident Game.
+
+## Execution Plan
+
+1. Define foreground model types.
+ Add enums/structs for foreground owner and resident Game state in the most
+ local SystemOS module. The model must distinguish Game foreground, Game
+ paused/suspended, Hub foreground, and Shell task foreground.
+
+2. Add SystemOS storage.
+ Store the foreground model in `SystemOS` from
+ `crates/console/prometeu-system/src/os/system_os.rs` with initialization to
+ Hub/Home root.
+
+3. Wire lifecycle facade operations.
+ Extend lifecycle/session facades so firmware can request:
+ - set Game foreground;
+ - request Home from Game;
+ - set Shell foreground from Hub;
+ - close Shell and return to Hub;
+ - query current foreground owner;
+ - query resident Game task.
+
+4. Enforce cardinality.
+ Add checks that reject a second resident Game and a second foreground Shell
+ with typed lifecycle errors. Use existing `LifecycleError` style or add
+ precise variants.
+
+5. Integrate existing Shell close behavior.
+ Update `crates/console/prometeu-firmware/src/firmware/firmware_step_shell_running.rs`
+ only where needed so closing a Shell task routes through the foreground model
+ and ends in `FirmwareState::HubHome`.
+
+6. Add tests.
+ Cover initial Hub foreground, Game foreground registration, Home request
+ moving Game to resident paused/suspended state, Shell foreground activation,
+ Shell close returning to Hub, and cardinality rejection.
+
+## Acceptance Criteria
+
+- SystemOS has an explicit foreground owner model.
+- Hub/Home is the initialized root foreground owner.
+- Only one resident Game can exist in v1.
+- Only one Shell task can be foreground in v1.
+- VM-backed Shell close returns to Hub/Home.
+- Foreground queries are available to firmware and later plans.
+- No implementation path enables background execution.
+
+## Tests / Validation
+
+- Add focused unit tests in `prometeu-system` around the new model and facade.
+- Run `cargo test -p prometeu-system lifecycle foreground`.
+- Run `cargo test -p prometeu-firmware shell`.
+- Run `discussion validate`.
+
+## Risks
+
+- Existing `TaskState::Foreground` and `TaskState::Suspended` may look like the
+ complete model. Do not overload them until foreground ownership and Hub root
+ authority are explicit.
+- Shell windows already have focus semantics. Keep window focus as visual/task
+ evidence, not the sole source of SystemOS foreground truth.
diff --git a/discussion/workflow/plans/PLN-0138-specify-foreground-pause-and-home-contract.md b/discussion/workflow/plans/PLN-0138-specify-foreground-pause-and-home-contract.md
new file mode 100644
index 00000000..78ad1dea
--- /dev/null
+++ b/discussion/workflow/plans/PLN-0138-specify-foreground-pause-and-home-contract.md
@@ -0,0 +1,114 @@
+---
+id: PLN-0138
+ticket: foreground-stack-game-pause-shell-vm-backed
+title: Specify Foreground Pause and Home Contract
+status: open
+created: 2026-07-03
+ref_decisions: [DEC-0037]
+tags: [runtime, specs, lifecycle, input, renderer, foreground]
+---
+
+## Briefing
+
+`DEC-0037` establishes the v1 foreground stack contract: one foreground visual
+owner, one resident Game, one foreground Shell, Hub as root, Game-visible
+pause/resume, OS-owned suspension, desktop `Esc` as Home/SystemOS request, and
+render epoch invalidation across foreground transitions.
+
+This plan updates the canonical runtime specs before implementation so code
+plans cannot drift into guest-owned Home input, background execution, or stale
+frame presentation.
+
+## Decisions of Origin
+
+- `DEC-0037` - Foreground Stack and Game Pause Contract.
+
+## Target
+
+Document the foreground, pause/suspend, Home request, input, audio, and render
+ownership contract in the canonical runtime specs.
+
+## Scope
+
+- Update `docs/specs/runtime/12-firmware-pos-and-prometeuhub.md` with:
+ - Hub as root/special Shell owner;
+ - one foreground visual owner;
+ - one resident Game;
+ - one foreground Shell;
+ - `Game -> Home/Shell -> same Game` lifecycle;
+ - VM-backed Shell app return-to-Hub behavior.
+- Update `docs/specs/runtime/06-input-peripheral.md` with:
+ - Home/SystemOS as host/system control, not pad input;
+ - desktop `Esc` as primary Home request;
+ - physical `Home` key as optional alias;
+ - input clear/barrier requirements across Game pause/resume.
+- Update `docs/specs/runtime/09-events-and-concurrency.md` with:
+ - pause notification budget;
+ - OS-owned suspension after the budget;
+ - resume/foreground-restore notification before visual return.
+- Update `docs/specs/runtime/14-boot-profiles.md` only to clarify that this
+ foreground contract is not Game-to-Game switching and does not change direct
+ `--run` or `--games-root` boot semantics.
+- Update renderer-related spec text in the most local existing runtime spec if
+ present, otherwise add a short subsection to `12-firmware-pos-and-prometeuhub.md`
+ describing ownership epoch invalidation and first-valid-frame gating.
+
+## Out of Scope
+
+- No Rust implementation.
+- No new guest ABI or pad button.
+- No background execution policy.
+- No Game A -> Home -> Game B switching.
+- No memory eviction policy for resident Games.
+
+## Execution Plan
+
+1. Edit `12-firmware-pos-and-prometeuhub.md`.
+ Define foreground owner cardinality, Hub root ownership, Shell foreground
+ behavior, Game resident/suspended behavior, return-to-Hub from Shell, and the
+ requirement to keep Hub/Shell visible until a resumed Game submits a valid
+ current-epoch frame.
+
+2. Edit `06-input-peripheral.md`.
+ State that Home/SystemOS is outside the guest-visible pad and input
+ intrinsic surface. Document desktop `Esc` as the primary host mapping and
+ physical `Home` as an optional alias.
+
+3. Edit `09-events-and-concurrency.md`.
+ Add the pause/resume event ordering: Home request, pause notification,
+ bounded reaction budget, OS suspension, resume/foreground-restore
+ notification, first-valid-frame visual return.
+
+4. Edit `14-boot-profiles.md`.
+ Cross-reference the foreground contract and explicitly keep direct boot,
+ games-root Home launch, and future Game-to-Game switching separate.
+
+5. Run text checks.
+ Search for wording that implies Home is a guest input button, a guest ABI, or
+ background execution. Replace misleading text with the `DEC-0037` contract.
+
+## Acceptance Criteria
+
+- Specs define `Paused` as Game-visible and `Suspended` as OS-owned.
+- Specs state that desktop `Esc` is the primary Home request and is not guest
+ pad input.
+- Specs state that the Game receives pause/resume notifications but does not
+ control OS suspension.
+- Specs state that Hub is the root Shell owner and Shell app close returns to
+ Hub in v1.
+- Specs state that visual return to Game waits for a valid current-epoch render
+ submission.
+- Specs explicitly exclude background execution and Game-to-Game switching.
+
+## Tests / Validation
+
+- Run `discussion validate`.
+- Run `rg -n "Home|Esc|Suspended|Paused|foreground|background execution" docs/specs/runtime`.
+- Verify no edited spec describes Home/SystemOS as a guest-visible pad button.
+
+## Risks
+
+- The spec could accidentally reopen Game-to-Game switching; keep that scoped to
+ `DSC-0043 / AGD-0044`.
+- The input spec could confuse physical keyboard mapping with VM input; keep
+ host/system controls outside the guest input surface.
diff --git a/discussion/workflow/plans/PLN-0139-validate-game-home-shell-game-end-to-end.md b/discussion/workflow/plans/PLN-0139-validate-game-home-shell-game-end-to-end.md
new file mode 100644
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--- /dev/null
+++ b/discussion/workflow/plans/PLN-0139-validate-game-home-shell-game-end-to-end.md
@@ -0,0 +1,106 @@
+---
+id: PLN-0139
+ticket: foreground-stack-game-pause-shell-vm-backed
+title: Validate Game Home Shell Game End To End
+status: open
+created: 2026-07-03
+ref_decisions: [DEC-0037]
+tags: [runtime, validation, firmware, host, lifecycle]
+---
+
+## Briefing
+
+`DEC-0037` is not complete until the product flow is proven end to end:
+a Game runs, the user requests Home, the Game is paused/suspended, Hub or a
+VM-backed Shell takes foreground, closing Shell returns to Hub, and the same
+Game can resume only after a valid current-epoch frame exists.
+
+This plan adds final validation after the spec, SystemOS, VM, host input, and
+render/audio/input boundary plans are implemented.
+
+## Decisions of Origin
+
+- `DEC-0037` - Foreground Stack and Game Pause Contract.
+
+## Target
+
+Prove the complete `Game -> Home/Shell -> same Game` lifecycle and prevent
+regressions around guest input, foreground authority, and stale rendering.
+
+## Scope
+
+- Add integration-style tests for:
+ - Game running to Home request;
+ - pause notification and forced suspension;
+ - Hub foreground while Game is resident;
+ - VM-backed Shell foreground while Game is suspended;
+ - Shell close returning to Hub;
+ - resume request returning to same Game;
+ - first-valid-frame visual restore;
+ - host `Esc`/`Home` not entering guest input.
+- Add manual smoke instructions for desktop host.
+- Confirm direct `--run` and games-root Home launch remain separate.
+
+## Out of Scope
+
+- No new implementation beyond tests and developer-facing validation notes.
+- No Game A -> Home -> Game B switching.
+- No performance tuning.
+- No polished UI.
+
+## Execution Plan
+
+1. Add firmware/SystemOS integration tests.
+ Use the most stable existing seams in `crates/console/prometeu-firmware/src/firmware/firmware.rs`
+ and `crates/console/prometeu-system` tests to drive Game foreground, Home
+ request, Shell foreground, Shell close, and Game resume.
+
+2. Add host input integration tests.
+ Ensure `Esc` and physical `Home` create a host Home event and do not mutate
+ guest `InputSignals`.
+
+3. Add render publication validation.
+ Assert stale submissions from the pre-pause Game epoch are rejected after
+ Home takes foreground and that the Game is not visually restored until a new
+ current-epoch submission exists.
+
+4. Add audio/input boundary validation.
+ Assert Game input is cleared or barriered across pause/resume. Assert Game
+ audio pause follows Game suspension.
+
+5. Add direct boot and games-root regression checks.
+ Ensure direct `--run ` remains independent from Home request handling
+ and that games-root Home launch still enters the Game path.
+
+6. Document manual smoke commands.
+ Add or update developer-facing spec text with release-mode commands:
+ - `cargo run --release -p prometeu-host-desktop-winit -- --run test-cartridges/stress-console`
+ - `cargo run --release -p prometeu-host-desktop-winit -- --games-root test-cartridges`
+ Include the expected `Esc -> Home -> Shell -> Hub -> resume Game` behavior
+ once implemented.
+
+## Acceptance Criteria
+
+- Automated tests cover `Game -> Home -> same Game`.
+- Automated tests cover `Game -> Home -> Shell -> Hub -> same Game`.
+- Tests prove Home request is host/SystemOS control, not guest pad input.
+- Tests prove suspended Game does not tick.
+- Tests prove stale render submissions are not presented.
+- Tests prove visual return waits for a current-epoch Game frame.
+- Direct `--run` and games-root Home launch regressions pass.
+
+## Tests / Validation
+
+- Run `cargo test -p prometeu-system`.
+- Run `cargo test -p prometeu-firmware`.
+- Run `cargo test -p prometeu-host-desktop-winit`.
+- Run any targeted render worker tests affected by ownership epoch changes.
+- Run `discussion validate`.
+
+## Risks
+
+- The current test seams may not expose enough host-driven lifecycle behavior.
+ If needed, add narrow test-only helpers rather than testing through sleeps or
+ real-time window loops.
+- End-to-end validation can become flaky if it depends on wall-clock timing.
+ Use deterministic ticks and explicit state transitions.
diff --git a/discussion/workflow/plans/PLN-0140-deliver-game-pause-resume-and-suspension.md b/discussion/workflow/plans/PLN-0140-deliver-game-pause-resume-and-suspension.md
new file mode 100644
index 00000000..32cf8eba
--- /dev/null
+++ b/discussion/workflow/plans/PLN-0140-deliver-game-pause-resume-and-suspension.md
@@ -0,0 +1,110 @@
+---
+id: PLN-0140
+ticket: foreground-stack-game-pause-shell-vm-backed
+title: Deliver Game Pause Resume and Suspension
+status: open
+created: 2026-07-03
+ref_decisions: [DEC-0037]
+tags: [runtime, os, vm, lifecycle, pause, suspension]
+---
+
+## Briefing
+
+`DEC-0037` separates Game-visible `Paused` from OS-owned `Suspended`. When Home
+is requested during Game execution, SystemOS must notify the Game, give it a
+short bounded budget, then suspend the VM even if the Game does not cooperate.
+When returning, SystemOS must reactivate the VM and send a resume or
+foreground-restore notification before the visual owner returns to Game.
+
+This plan implements the pause/resume and suspension mechanics after the
+foreground state model exists.
+
+## Decisions of Origin
+
+- `DEC-0037` - Foreground Stack and Game Pause Contract.
+
+## Target
+
+Add Game pause/resume lifecycle delivery and OS-enforced VM suspension for the
+same resident Game.
+
+## Scope
+
+- Add a Game lifecycle event model for pause and resume/foreground-restore.
+- Add a bounded pause reaction budget owned by SystemOS.
+- Suspend the Game VM after the budget even if the Game does not cooperate.
+- Ensure a suspended Game receives no normal gameplay ticks.
+- Reactivate the VM and deliver resume/foreground-restore before Game visual
+ foreground restoration.
+- Integrate with `GameRunningStep` and VM runtime tick control.
+
+## Out of Scope
+
+- No render first-valid-frame gating; that is in `PLN-0141`.
+- No host keyboard routing; that is in `PLN-0136`.
+- No new guest syscall.
+- No background execution.
+- No Game-to-Game switching.
+
+## Execution Plan
+
+1. Add lifecycle event representation.
+ Define pause/resume events in the most local runtime lifecycle module,
+ likely under `crates/console/prometeu-system/src/os/lifecycle.rs` or a new
+ SystemOS lifecycle submodule. Events must be observable by the VM/runtime
+ path without giving the Game authority over suspension.
+
+2. Add pause transition state.
+ Extend the foreground state from `PLN-0137` with a `PauseRequested` or
+ equivalent transition state that records the target Game task and the
+ remaining pause budget.
+
+3. Gate VM ticks.
+ Update `crates/console/prometeu-firmware/src/firmware/firmware_step_game_running.rs`
+ and `crates/console/prometeu-system/src/services/vm_runtime/tick.rs` so a
+ suspended Game does not receive normal ticks, normal input, or frame pacing.
+
+4. Deliver pause notification.
+ Add the mechanism that makes the pause event visible to the running Game
+ before suspension. Use an existing VM event channel if present; otherwise add
+ a narrow lifecycle-event queue owned by SystemOS/VM runtime.
+
+5. Enforce the budget.
+ Advance the pause budget on firmware ticks. When it expires, transition the
+ Game task/process to suspended through SystemOS lifecycle regardless of Game
+ cooperation.
+
+6. Deliver resume notification.
+ On return to the resident Game, transition from suspended to resume-requested,
+ reactivate VM execution, deliver resume/foreground-restore, and leave visual
+ restoration to the render boundary plan.
+
+7. Add tests.
+ Cover cooperative pause, non-cooperative forced suspension, no tick while
+ suspended, resume notification delivery, and no Game-owned ability to cancel
+ OS suspension.
+
+## Acceptance Criteria
+
+- Game receives pause before suspension.
+- SystemOS suspends after a bounded budget even if the Game does not cooperate.
+- Suspended Game does not receive normal gameplay ticks.
+- Resume/foreground-restore is delivered before visual return to Game.
+- Game cannot prevent OS suspension through guest-visible behavior.
+- Existing debugger pause behavior remains distinct from lifecycle suspension.
+
+## Tests / Validation
+
+- Add unit tests in `prometeu-system` for lifecycle transition state.
+- Add firmware tests around `GameRunningStep` pause request and suspension.
+- Add VM runtime tests proving suspended state suppresses normal ticks.
+- Run `cargo test -p prometeu-system`.
+- Run `cargo test -p prometeu-firmware`.
+- Run `discussion validate`.
+
+## Risks
+
+- Debugger pause already exists in VM runtime. Keep debug pause separate from
+ lifecycle pause/suspend.
+- A lifecycle event queue could become a general app event system. Keep this
+ plan limited to pause/resume required by `DEC-0037`.
diff --git a/discussion/workflow/plans/PLN-0141-integrate-render-audio-and-input-pause-boundaries.md b/discussion/workflow/plans/PLN-0141-integrate-render-audio-and-input-pause-boundaries.md
new file mode 100644
index 00000000..710caeb2
--- /dev/null
+++ b/discussion/workflow/plans/PLN-0141-integrate-render-audio-and-input-pause-boundaries.md
@@ -0,0 +1,104 @@
+---
+id: PLN-0141
+ticket: foreground-stack-game-pause-shell-vm-backed
+title: Integrate Render Audio and Input Pause Boundaries
+status: open
+created: 2026-07-03
+ref_decisions: [DEC-0037]
+tags: [runtime, renderer, audio, input, foreground, lifecycle]
+---
+
+## Briefing
+
+`DEC-0037` requires foreground transitions to invalidate stale render
+submissions, keep Hub/Shell visible until the resumed Game publishes a valid
+current-epoch frame, clear or barrier Game input across pause/resume, and pause
+Game audio with the Game VM in v1.
+
+This plan integrates those boundary effects after SystemOS foreground state and
+Game pause/resume mechanics exist.
+
+## Decisions of Origin
+
+- `DEC-0037` - Foreground Stack and Game Pause Contract.
+
+## Target
+
+Make foreground transitions safe at the render, input, and audio boundaries.
+
+## Scope
+
+- Advance render ownership epoch/generation whenever foreground owner changes.
+- Discard stale Game frames after Shell/Hub takes foreground.
+- Discard stale Shell frames after Game resumes.
+- Keep Hub/Shell visible until a resumed Game publishes a valid current-epoch
+ submission.
+- Clear or barrier Game input across pause/resume boundaries.
+- Pause Game audio with the Game VM in v1.
+- Add telemetry/tests for stale discards and first-valid-frame gating.
+
+## Out of Scope
+
+- No independent background audio policy.
+- No overlay rendering policy.
+- No Game-to-Game switch rendering.
+- No full memory eviction behavior.
+
+## Execution Plan
+
+1. Extend render ownership transition calls.
+ Update `crates/console/prometeu-system/src/services/vm_runtime/render_manager.rs`
+ and call sites in `tick.rs` so foreground owner changes explicitly advance
+ ownership epoch/generation, not only app mode/app id changes.
+
+2. Add foreground restore gating.
+ Add state in SystemOS or firmware that records when visual return to Game is
+ pending. The state must remain in Hub/Shell presentation until a
+ current-epoch Game submission is observed.
+
+3. Update host presentation selection.
+ Update `crates/host/prometeu-host-desktop-winit/src/runner.rs` if necessary
+ so `should_present_worker_frame` and fallback framebuffer presentation obey
+ the foreground restore gate.
+
+4. Add stale discard coverage.
+ Extend render manager and render worker tests to prove stale submissions
+ from the previous owner are discarded after epoch change.
+
+5. Add input boundary clearing.
+ Add a SystemOS or firmware input barrier when Game pause starts and when
+ Game resume starts. The barrier must prevent held or pressed Game input from
+ leaking across the lifecycle boundary.
+
+6. Add audio pause integration.
+ Ensure Game pause/suspend produces the existing host audio pause command path
+ or a new explicit lifecycle audio pause signal. Keep this separate from
+ debugger pause if the observable cause matters in tests.
+
+7. Add tests.
+ Cover stale frame discard, first-valid-frame visual return, input clearing,
+ and Game audio pause/resume behavior.
+
+## Acceptance Criteria
+
+- Foreground owner changes advance render ownership epoch/generation.
+- Old Game frames cannot present after Hub/Shell takes foreground.
+- Old Hub/Shell frames cannot present after Game resumes.
+- Visual return to Game waits for a valid current-epoch Game submission.
+- Game input does not leak across pause/resume boundaries.
+- Game audio pauses with Game suspension in v1.
+
+## Tests / Validation
+
+- Run `cargo test -p prometeu-system render foreground`.
+- Run `cargo test -p prometeu-firmware pause`.
+- Run `cargo test -p prometeu-host-desktop-winit presentation`.
+- Run `discussion validate`.
+
+## Risks
+
+- Existing render epoch logic may already key off app mode/app id. Foreground
+ owner changes must be explicit so Shell/Hub and resumed Game cannot share a
+ stale epoch by accident.
+- Audio pause currently follows VM paused/debugger state in the host. Keep Game
+ lifecycle pause distinct enough that tests can prove the decision contract.