---
id: PLN-0052
ticket: system-os-service-ownership-and-module-layout
title: Promote Window Manager To SystemOS Service
status: open
created: 2026-05-14
ref_decisions: [DEC-0024]
tags: [runtime, os, services, module-layout, vm, window-manager, logging]
---

## Briefing

Promote `WindowManager` from a `PrometeuHub` private module into an OS service
owned or mediated by `SystemOS`, as required by `DEC-0024`.

## Source Decisions

- `DEC-0024`: `WindowManager` SHALL move to the services tree and SHALL be
  owned or mediated by `SystemOS`; `PrometeuHub` MUST NOT own it as an OS
  service.

## Target

Make `WindowManager` part of the `services` tree and stop treating
`PrometeuHub` as the owner of window management.

## Dependencies

- Source decision: `DEC-0024`.
- Depends on `PLN-0051` only for the general service layout convention.

## Scope

- Move `crates/console/prometeu-system/src/programs/prometeu_hub/window_manager.rs`
  into the `services` tree.
- Expose the service from `crates/console/prometeu-system/src/services/mod.rs`.
- Add a `WindowManager` field or OS-mediated access path on `SystemOS`.
- Remove `window_manager` ownership from `PrometeuHub`.
- Update `PrometeuHub` to access window management through `SystemOS`.
- Update tests and imports directly.

## Out of Scope

- Do not implement new windowing behavior.
- Do not define surface/window lifecycle beyond the existing minimal behavior.
- Do not introduce old-path compatibility reexports.
- Do not change task/process lifecycle semantics.

## Execution Plan

1. Move the `WindowManager` module into `src/services/`.
2. Register the new service module in `services/mod.rs`.
3. Add `WindowManager` initialization to `SystemOS::new`.
4. Remove `WindowManager` storage from `PrometeuHub`.
5. Update Hub methods so their window manager access is mediated by `SystemOS`.
6. Update tests for the new module path and ownership location.
7. Run formatting and the affected tests.

## Acceptance Criteria

- `WindowManager` no longer lives under `programs/prometeu_hub`.
- `PrometeuHub` does not own a `WindowManager` field.
- `SystemOS` owns or mediates access to `WindowManager`.
- No old `programs::prometeu_hub::window_manager` path remains available.
- Existing Hub behavior remains unchanged.

## Tests / Validation

- Run `cargo test -p prometeu-system`.
- Include any focused tests for `WindowManager` after the move.

## Risks

- `PrometeuHub` currently owns its `WindowManager`; moving ownership may require
  method signatures to pass through `SystemOS` cleanly.
- The implementation must not accidentally introduce new window/surface
  semantics while moving ownership.

## Affected Artifacts

- `crates/console/prometeu-system/src/programs/prometeu_hub/mod.rs`
- `crates/console/prometeu-system/src/programs/prometeu_hub/prometeu_hub.rs`
- `crates/console/prometeu-system/src/services/mod.rs`
- `crates/console/prometeu-system/src/services/window_manager.rs` or equivalent
- `crates/console/prometeu-system/src/os/system_os.rs`