Add semantic parity comparator and fixture suite

[jununfly]

This was generated by AI during triage.

Parent

#49 - PRD: Rust indexing core vertical slice

What to build

Add a semantic parity comparator and fixture suite that compares the Rust and TypeScript extraction paths by graph meaning rather than byte-identical database output.

Acceptance criteria

• A comparator can compare TypeScript and Rust extraction outputs semantically.
• The comparison covers file nodes, named functions/classes/methods/components, imports/exports, contains edges, local calls, unresolved references, and source locations within an accepted tolerance.
• Differences are categorized as expected, acceptable, or blocking.
• Fixture parity coverage exists for plain JavaScript, TypeScript, JSX, TSX, object-literal methods, imports/exports/re-exports, and component usage.
• Real-repo parity checks are available for this repository and Excalidraw.

Blocked by

#53

[jununfly]

Implemented and verified. Semantic parity comparator, fixture parity coverage, and real-repo parity check script are in place. See c17a1e4 and preceding Rust Phase 1 commits.