Foundation for upcoming editor features (scope-aware autocomplete,
goto-def / find-usages, source formatter). Hand-rolled recursive
descent in TypeScript with Pratt precedence climbing for expressions,
error-tolerant so partial trees stay usable while the user is typing.
Symbol table walks the AST to produce per-scope declarations, usage
sites, and object-literal field maps. Vitest added as a dev-only
runner; no editor wiring in this commit.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
