refactor(docs): extract typed endpoint registry

[samjay8]

Closes #476

Related #512

📖 Refactor: Extract Typed Endpoint Registry Consumed by Docs Page

Centralizes all API endpoint definitions into a single typed registry module, eliminating inline hard-coding on the docs page and making documentation automatically stay in sync with the registry. No new dependencies added. Visual output unchanged.

Changes

src/lib/endpoints.ts (new)

• Defines EndpointParam and Endpoint TypeScript interfaces for consistent structure across all entries
• Single source of truth for all API endpoints (method, path, description, params)
• Populated with all endpoints from the project README — easy to update in one place

src/app/docs/page.tsx

• Removed all hard-coded inline endpoint sections
• Now imports endpoints array from registry and maps over it to render each endpoint
• Visual output is identical to the previous version

src/app/docs/page.test.tsx

• Overhauled test suite to import endpoints registry directly
• Programmatically asserts every endpoint and its parameters render correctly on the page
• Added edge case coverage:
  • Endpoint with no parameters
  • Empty registry

Checklist

• ✅ npm run lint — passes
• ✅ npm test — passes
• ✅ npm run build — passes
• ✅ 95%+ test coverage on impacted modules
• ✅ No new dependencies
• ✅ Visual output unchanged