fix(cha): CHA dispatch omits the receiver's own instantiated type

[carlos-alm]

Summary

• Issue follow-up: odd zero-line "file calls itself" edges (module-level dispatch?) — WASM-only #2348's title framed this as a WASM-only "file calls itself" oddity — investigation found the file-as-caller pattern is legitimate, intentional module-level-code representation (shared by both engines), not a bug. But a SEPARATE, real bug was found while investigating the issue's specific quoted example (in-memory-repository.test.ts → BrokenRepo.findNodesForTriage in an unrelated test file).
• Root cause: resolveChaTargets (cha.ts) / resolve_cha_dispatch (build_edges.rs) BFS-walk only ever considered the receiver's subclasses as dispatch targets — it never checked whether the receiver's own declared type is itself instantiated and should resolve to its own method. When a base class (InMemoryRepository) is instantiated directly AND an unrelated file declares a local subclass overriding the same method (test doubles BrokenRepo/InvalidOptsRepo, declared inside it() callbacks in a completely different test file), the base class's own correct method was silently dropped from the resolved edge set while the unrelated subclass's override leaked in instead.
• Fix: both engines now also resolve the receiver's own type via resolveMethodViaAncestors/resolve_method_via_ancestors, gated on a new strict new-expression-only evidence set (newExpressionTypes/cha_new_expression_types) rather than the merged instantiatedTypes/cha_instantiated_types set (which also credits a bare high-confidence type annotation as "instantiated" — too weak for this particular check, since it would resurrect a distant interface's own bodyless method whenever an unrelated concrete subclass overrides the same method name elsewhere). This distinction was discovered because applying the naive fix against the merged set regressed two existing native unit tests.
• The existing seenCallEdges dedup makes this fix strictly additive — it can only add a previously-missing edge, never introduce a duplicate or wrong one.
• Issue follow-up: possible WASM cross-fixture-directory false positives in super-dispatch (jelly-micro classes/super/super4/super5) #2347 (a related deferred observation from the same parent issue bug: native engine misses call edges when receiver's static type is an interface with multiple implementers (NativeDbProxy, TreeSitterNode, Repository) #2139) was independently verified as already fixed by bug(parity): WASM emits spurious cross-file super() constructor edges to unrelated same-named classes (jelly-micro) #2238/WASM super-dispatch falls back to unrelated same-named classes when the parent is a function-style pseudo-class #2244 and closed separately, with no code changes.

Test plan

• New dual-engine regression test tests/integration/issue-2348-cha-base-type-own-method.test.ts — synthetic fixture mirroring the real repro shape (base class instantiated directly + two unrelated local subclass overrides in separate files); verified to fail on both engines with the fix disabled, pass with it enabled
• Directly re-verified against the actual real-world repro (this repo's own tests/unit/in-memory-repository.test.ts/tests/integration/triage.test.ts): InMemoryRepository.findNodesForTriage now correctly appears as a target for both engines (additive alongside the pre-existing, harmless spurious edges)
• cargo test --workspace: 1011 passed (was 1009 passed / 2 failed against the naive fix, before the strict-evidence refinement)
• cargo fmt --check / cargo clippy --workspace --all-targets -- -D warnings: clean
• Full test suite: 328 files / 5257 tests passed
• npm run lint clean

Closes #2348

[greptile-apps]

Greptile Summary

This follow-up scopes receiver-own-type instantiation evidence by declaring file, preventing unrelated same-named local types from producing spurious CHA targets while preserving the intended base-type edge.

• Adds file-scoped construction and declaration evidence to both TypeScript and Rust CHA contexts.
• Uses scoped evidence for receiver-own-type dispatch when the caller file declares the receiver type.
• Adds mirrored unit and integration coverage for native and WASM engines.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
src/domain/graph/builder/cha.ts	Adds strict, file-scoped receiver instantiation evidence and uses it to disambiguate local same-named types during CHA dispatch.
crates/codegraph-core/src/domain/graph/builder/stages/build_edges.rs	Mirrors the TypeScript CHA scoping behavior in the native Rust edge builder.
src/domain/graph/builder/stages/native-orchestrator.ts	Initializes the expanded CHA context used by post-native this/super dispatch.
tests/integration/issue-2348-cha-base-type-own-method.test.ts	Verifies both engines retain the instantiated base type’s own method as a call target.
tests/unit/cha.test.ts	Covers same-named local-type disambiguation and the explicitly retained imported-type fallback.

_{Reviews (2): Last reviewed commit: "fix(cha): scope receiver-own-type RTA ev..." | Re-trigger Greptile}

[github-actions]

Codegraph Impact Analysis

5 functions changed → 22 callers affected across 8 files

• collectInstantiatedTypes in src/domain/graph/builder/cha.ts:213 (3 transitive callers)
• buildChaContext in src/domain/graph/builder/cha.ts:247 (3 transitive callers)
• buildChaContextFromDb in src/domain/graph/builder/cha.ts:325 (12 transitive callers)
• resolveChaTargets in src/domain/graph/builder/cha.ts:818 (9 transitive callers)
• runPostNativeThisDispatch in src/domain/graph/builder/stages/native-orchestrator.ts:1461 (3 transitive callers)