feat: add GET /hello endpoint for bot detection verification

[therealsaitama0]

Summary

Closes #120

Adds the GET /hello endpoint that returns { "ok": true } to verify bot detection, as required by issue #120.

Changes

• apps/api/src/app.ts — Added a root-level GET /hello route returning { ok: true } with HTTP 200.
• apps/api/src/routes/api.ts — Added GET /hello to the API sub-router (accessible as GET /api/hello) and registered it in the public endpoint documentation metadata.
• apps/api/src/app.test.ts (new) — Integration test verifying GET /hello responds 200 with { ok: true } at the app level.
• apps/api/src/routes/api.test.ts — Added test for GET /api/hello in the public endpoints suite.

Acceptance Criteria

• Route responds 200
• JSON body is { "ok": true }
• PR references issue [BOUNTY $50] Add a hello-world test endpoint to verify bot detection #120

Test Results

All 21 test suites (153 tests) pass:

Test Suites: 21 passed, 21 total
Tests:       153 passed, 153 total

ESLint and TypeScript type-checking also pass cleanly.