Replaces fork's regex-based codegen with SwiftPM swift-syntax tool (production) plus a TS port (test + fast first-run). Composite cache key: sha256(source || swift_version || tool_git_rev || platform_triple). Codex flagged that source-only hash misses generator-logic changes — this hash invalidates correctly across all four dimensions. 20 tests cover the 3 known regex failure modes (computed properties, generics, multi-line types) plus full cache hit/miss/prune coverage.
Garry Tan