added new prs

docs/pbs/pull-requests/INDEX.md

@@ -17,3 +17,15 @@ Este indice organiza uma sequencia de PRs atomicas para levar `frontends/pbs` ao
 13. `PR-011-pbs-gate-u-conformance-fixtures.md`
 
 Cada documento e auto contido e inclui: `Briefing`, `Target`, `Method`, `Acceptance Criteria` e `Tests`.
+
+## Non-Conformance Remediation PRs
+
+14. `PR-012-pbs-byte-offset-spans.md`
+15. `PR-013-pbs-import-unresolved-diagnostics.md`
+16. `PR-014-pbs-switch-wildcard-rules.md`
+17. `PR-015-pbs-this-self-context-validation.md`
+18. `PR-016-pbs-assignment-target-and-field-access-semantics.md`
+19. `PR-017-pbs-const-evaluation-and-dependency-rules.md`
+20. `PR-018-pbs-result-flow-ok-err-handle-rules.md`
+21. `PR-019-pbs-non-unit-fallthrough-diagnostics.md`
+22. `PR-020-pbs-lowering-admission-gates.md`

docs/pbs/pull-requests/PR-012-pbs-byte-offset-spans.md

@@ -0,0 +1,45 @@
+# PR-012 - PBS Lexer Byte-Offset Spans
+
+## Briefing
+
+Lexer spans are currently tracked as Java `String` character indices. The PBS syntax spec requires stable byte offsets. This PR aligns token/span attribution with byte offsets and keeps diagnostics deterministic.
+
+## Motivation
+
+Without byte offsets, diagnostics and downstream attribution diverge on non-ASCII sources, violating the lexical contract.
+
+## Target
+
+- `prometeu-frontend-pbs` lexer and span attribution behavior.
+- Diagnostics and AST attribution consumers that depend on lexer spans.
+
+## Scope
+
+- Convert lexer position accounting to UTF-8 byte offsets.
+- Preserve existing tokenization semantics.
+- Keep parser/semantics APIs unchanged.
+
+## Method
+
+- Introduce byte-accurate cursor accounting in lexer scanning.
+- Emit token start/end using byte offsets.
+- Validate compatibility with parser and diagnostics sinks.
+- Add regression fixtures with non-ASCII source content.
+
+## Acceptance Criteria
+
+- All emitted tokens include UTF-8 byte offsets.
+- Diagnostics from lexer/parser over non-ASCII sources point to correct byte spans.
+- Existing ASCII tests remain green.
+- New non-ASCII span tests are added and deterministic.
+
+## Tests
+
+- Extend lexer tests with UTF-8 multibyte identifiers/strings.
+- Add parser span-attribution tests over multibyte source.
+- Run full `prometeu-frontend-pbs` test suite.
+
+## Non-Goals
+
+- Changing token classes or grammar.
+- Changing message wording policy.

docs/pbs/pull-requests/PR-013-pbs-import-unresolved-diagnostics.md

@@ -0,0 +1,44 @@
+# PR-013 - PBS Unresolved Import Diagnostics
+
+## Briefing
+
+Import resolution currently ignores missing target modules in frontend linking validation. This PR enforces deterministic diagnostics for unresolved module imports and unresolved imported symbols.
+
+## Motivation
+
+Silent import misses break the diagnostics contract and defer user-actionable errors.
+
+## Target
+
+- Module import validation in `PbsModuleVisibilityValidator`.
+- Linking diagnostic coverage for import failures.
+
+## Scope
+
+- Emit errors for missing target module references.
+- Keep existing public-symbol checks.
+- Preserve deterministic, source-first attribution.
+
+## Method
+
+- Extend import validation to detect absent target modules.
+- Report diagnostics on the importing site.
+- Keep related-span behavior where applicable.
+
+## Acceptance Criteria
+
+- Importing a non-existent module always emits deterministic linking/import diagnostic.
+- Importing a non-public symbol still emits existing diagnostic.
+- Diagnostic attribution points to import site.
+- No silent pass for unresolved imports remains.
+
+## Tests
+
+- Add tests for missing module import.
+- Add tests for missing symbol import in existing module.
+- Verify phase and diagnostic code stability.
+
+## Non-Goals
+
+- Full manifest/dependency resolver redesign.
+- Loader/runtime capability checks.

docs/pbs/pull-requests/PR-014-pbs-switch-wildcard-rules.md

@@ -0,0 +1,42 @@
+# PR-014 - PBS Switch Wildcard Rule Enforcement
+
+## Briefing
+
+Switch semantics do not currently enforce all wildcard constraints. This PR enforces: at most one wildcard arm, and rejection of mixed `default` and `_` in the same switch.
+
+## Motivation
+
+Wildcard ambiguity weakens deterministic static semantics and conformance.
+
+## Target
+
+- Switch expression semantic validation in flow analyzer.
+- Required static diagnostics for wildcard rule violations.
+
+## Scope
+
+- Enforce wildcard-count and wildcard-mixing rules.
+- Preserve existing selector/type compatibility checks.
+
+## Method
+
+- Track wildcard token form used per switch arm.
+- Emit diagnostics for duplicate wildcard and mixed wildcard spellings.
+- Keep existing exhaustiveness behavior.
+
+## Acceptance Criteria
+
+- Two wildcard arms are rejected deterministically.
+- `default` + `_` in one switch is rejected deterministically.
+- Existing duplicate-pattern logic for non-wildcards remains unchanged.
+
+## Tests
+
+- Add tests for duplicate wildcard arms.
+- Add tests for mixed `default`/`_` arms.
+- Run semantic control-flow suite.
+
+## Non-Goals
+
+- New switch syntax.
+- Runtime switch lowering changes.

docs/pbs/pull-requests/PR-015-pbs-this-self-context-validation.md

@@ -0,0 +1,43 @@
+# PR-015 - PBS this/Self Context Validation
+
+## Briefing
+
+The frontend accepts `this` and `Self` outside allowed contexts without required diagnostics. This PR adds explicit static checks for invalid usage.
+
+## Motivation
+
+Context-free acceptance of `this`/`Self` is non-conformant and creates type ambiguity.
+
+## Target
+
+- `this` expression analysis.
+- `Self` type-surface analysis in declarations.
+- Error catalog and deterministic diagnostics.
+
+## Scope
+
+- Reject `this` outside struct method, service method, and ctor bodies.
+- Reject `Self` outside struct/service method declarations and ctors.
+
+## Method
+
+- Add callable-context metadata into flow/type validation.
+- Emit dedicated diagnostics for invalid `this` and invalid `Self` usage.
+- Keep valid owner contexts unchanged.
+
+## Acceptance Criteria
+
+- Invalid `this` usage emits deterministic static diagnostic.
+- Invalid `Self` usage emits deterministic static diagnostic.
+- Valid struct/service/ctor contexts remain accepted.
+
+## Tests
+
+- Add positive tests for valid `this`/`Self` contexts.
+- Add negative tests for top-level functions and unrelated declarations.
+- Run declaration + flow semantic suites.
+
+## Non-Goals
+
+- Introducing new receiver features.
+- Altering `Self` syntax.

docs/pbs/pull-requests/PR-016-pbs-assignment-target-and-field-access-semantics.md

@@ -0,0 +1,44 @@
+# PR-016 - PBS Assignment Target and Field Access Semantics
+
+## Briefing
+
+Assignment validation currently does not enforce target existence, assignability, mutability, or write-access constraints. This PR closes those gaps.
+
+## Motivation
+
+Unchecked assignment targets allow invalid programs through static semantics.
+
+## Target
+
+- Assignment statement semantic analysis.
+- Struct field read/write access validation (`private`, `pub`, `pub mut`).
+
+## Scope
+
+- Resolve LValue path against known symbols.
+- Validate assignment compatibility and write permissions.
+- Emit deterministic diagnostics for invalid target/write access.
+
+## Method
+
+- Add LValue resolver in flow semantic analyzer.
+- Use struct metadata (`isPublic`, `isMutable`) for access checks.
+- Distinguish read-access and write-access diagnostics.
+
+## Acceptance Criteria
+
+- Missing assignment target is rejected deterministically.
+- Writes to private fields from invalid contexts are rejected.
+- Writes to non-`pub mut` external fields are rejected.
+- Type mismatch in assignment is reported deterministically.
+
+## Tests
+
+- Add assignment tests for local, field, and nested member targets.
+- Add negative access tests (`pub` read-only vs `pub mut`).
+- Add type-mismatch assignment tests.
+
+## Non-Goals
+
+- New mutation syntax.
+- Runtime memory model changes.

docs/pbs/pull-requests/PR-017-pbs-const-evaluation-and-dependency-rules.md

@@ -0,0 +1,45 @@
+# PR-017 - PBS Const Evaluation and Dependency Rules
+
+## Briefing
+
+`declare const` validation only checks explicit type and initializer presence. This PR implements constant-expression legality, dependency ordering, cycle detection, and initializer type compatibility.
+
+## Motivation
+
+Const declarations are part of static semantics and must be deterministic across files.
+
+## Target
+
+- Const semantic validation layer.
+- Diagnostic coverage for constant expression failures.
+
+## Scope
+
+- Enforce allowed constant-expression subset.
+- Resolve const dependencies module-wide, independent of source-file order.
+- Reject cycles and unresolved const references.
+- Validate initializer type compatibility with declared const type.
+
+## Method
+
+- Build const dependency graph from top-level declarations.
+- Evaluate in topological order.
+- Emit stable diagnostics for disallowed forms and graph failures.
+
+## Acceptance Criteria
+
+- Non-constant initializer forms are rejected deterministically.
+- Cross-file const references resolve independent of source order.
+- Cycles are rejected deterministically.
+- Incompatible const initializer types are rejected.
+
+## Tests
+
+- Add const-expression positive/negative fixtures.
+- Add cross-file dependency and cycle tests.
+- Add type-compatibility tests.
+
+## Non-Goals
+
+- General compile-time function execution.
+- Runtime const materialization strategy changes.

docs/pbs/pull-requests/PR-018-pbs-result-flow-ok-err-handle-rules.md

@@ -0,0 +1,44 @@
+# PR-018 - PBS Result Flow (ok/err/handle) Rule Enforcement
+
+## Briefing
+
+Result-flow rules are only partially enforced. This PR enforces allowed positions for `ok/err`, error-label validation, and `handle` arm terminal form requirements.
+
+## Motivation
+
+Result-flow constructs are normative control-flow surfaces and must not behave as unconstrained expressions.
+
+## Target
+
+- `ok(...)` and `err(...)` validation in return-flow contexts.
+- `handle` semantic validation, including terminal form of block arms.
+
+## Scope
+
+- Restrict `ok/err` to allowed result-flow positions.
+- Validate `err(E.case)` against declared error type.
+- In `handle` block arms, enforce terminal `ok(payload)` or `err(E2.case)`.
+
+## Method
+
+- Add expression-use/context flags for result-flow forms.
+- Add dedicated diagnostics for invalid placement and invalid error labels.
+- Add terminal-check pass for handle block arms.
+
+## Acceptance Criteria
+
+- `ok/err` outside allowed positions are rejected deterministically.
+- `return ok/err` validates declared `result<E>` contract.
+- `handle` block arms violating terminal rules are rejected deterministically.
+- Existing propagate (`!`) and handle exhaustiveness checks remain stable.
+
+## Tests
+
+- Add positive and negative fixtures for `return ok/err`.
+- Add invalid-position tests for `ok/err` as ordinary expression.
+- Add `handle` arm terminal-form tests.
+
+## Non-Goals
+
+- New result syntax.
+- Runtime trap policy changes.

docs/pbs/pull-requests/PR-019-pbs-non-unit-fallthrough-diagnostics.md

@@ -0,0 +1,42 @@
+# PR-019 - PBS Non-Unit Fallthrough Diagnostics
+
+## Briefing
+
+The frontend does not currently reject fallthrough of plain non-unit functions and `result` functions at end-of-body paths. This PR adds control-flow completion checks.
+
+## Motivation
+
+Return-surface obligations are normative and must be statically enforced.
+
+## Target
+
+- Callable body completion validation for function/method/ctor contexts.
+
+## Scope
+
+- Reject plain non-unit callable bodies that may complete without explicit return.
+- Reject `result<E>` callable bodies that may complete without explicit return.
+- Preserve existing unit and optional fallthrough behavior.
+
+## Method
+
+- Add path-completion analysis over statement/block graph.
+- Integrate with existing flow body analyzer.
+- Emit deterministic diagnostics with stable code/phase.
+
+## Acceptance Criteria
+
+- Possible fallthrough on plain non-unit callable is rejected.
+- Possible fallthrough on `result<E>` callable is rejected.
+- `void` and `optional` callable fallthrough behavior remains valid.
+
+## Tests
+
+- Add positive/negative control-flow completion fixtures.
+- Cover nested `if`/`switch`/loop interactions.
+- Run full flow semantics suite.
+
+## Non-Goals
+
+- Dataflow-based optimization.
+- Runtime control-flow instrumentation.

docs/pbs/pull-requests/PR-020-pbs-lowering-admission-gates.md

@@ -0,0 +1,43 @@
+# PR-020 - PBS Lowering Admission Gates
+
+## Briefing
+
+Lowering currently proceeds even when syntax/static/linking diagnostics contain errors. This PR introduces explicit admission gates so invalid programs are rejected before IR lowering.
+
+## Motivation
+
+Lowering must not convert required rejections into accepted lowered artifacts.
+
+## Target
+
+- `PbsFrontendCompiler` and `PBSFrontendPhaseService` lowering flow.
+- Frontend-to-IR admission policy.
+
+## Scope
+
+- Block IR emission for source units with fatal diagnostics.
+- Preserve deterministic diagnostics already emitted by previous phases.
+- Keep successful paths unchanged.
+
+## Method
+
+- Introduce phase gate checks before `lowerFunctions` / file merge.
+- Ensure failed units are excluded from emitted IR.
+- Keep build issue adaptation behavior stable.
+
+## Acceptance Criteria
+
+- Files/modules with syntax/static/linking errors are not lowered.
+- No invalid callable appears in IR output after failed admission.
+- Valid files continue lowering unchanged.
+
+## Tests
+
+- Add tests proving failed parse/semantic/linking input does not emit IR functions.
+- Add tests proving clean input still emits expected IR.
+- Run frontend phase service and compiler suites.
+
+## Non-Goals
+
+- Redefining diagnostics severity policy.
+- Introducing partial lowering recovery strategy.