Add accessible endpoint search

[es3298]

Summary

• Add an accessible EndpointSearch component for ApiDetailPage documentation endpoints.
• Filter endpoint cards and group previews by title, path, method, group, parameter name/type, and required/optional status.
• Add a resettable no-results state and short docs for the visible behavior.
• Repair stale malformed JSX in ApiDetailPage so the documentation tab can render and be tested.

Closes #280

Validation

• npx vitest run src/components/EndpointSearch.test.tsx src/pages/ApiDetailPage.test.tsx (6 passed)
• git diff --check

Known baseline blocker

• npm run build is blocked by existing unrelated syntax errors in src/App.tsx at lines 1074-1076 before this change set is checked.