docs: update all documentation to reflect JS→TS migration
- README.md: TypeScript 5.9 in tech stack, test count 368+, evalRunner.ts
- CONTRIBUTING.md: TypeScript code examples, project structure with .ts/.tsx, PR checklist
- AGENTS.md: all src/ module references .js→.ts, TypeScript in stack
- ARCHITECTURE.md: 44 src/ path refs updated, date updated, TS/JS note
- CODEBASE_DOCUMENTATION.md: localDb.ts/usageDb.ts in app layer
- TASKS.md: 8 component/route refs updated to .tsx/.ts
open-sse/ references correctly remain .js (not yet migrated)
diegosouzapw
5ef97b2622