Add comprehensive testing infrastructure with 99.46% coverage

- Configure Jest with Next.js 15 and TypeScript
- Add 73 tests (API routes, components, config)
- Achieve 99.46% code coverage (100% on API routes)
- Set up GitHub Actions test workflow with Bun
- Configure pre-push hooks to run tests
- Add comprehensive testing documentation
- Fix YAML indentation and permissions in workflows
- Update all commands to use Bun exclusively

Author: iddhi-sulakshana

.github/workflows/test.yml

@@ -11,6 +11,11 @@ jobs:
         name: Run Tests
         runs-on: ubuntu-latest
 
+        permissions:
+            contents: read
+            pull-requests: write
+            issues: write
+
         strategy:
             matrix:
                 node-version: [20.x]
@@ -56,6 +61,7 @@ jobs:
             - name: Comment PR with coverage
               if: github.event_name == 'pull_request'
               uses: romeovs/lcov-reporter-action@v0.3.1
+              continue-on-error: true
               with:
                   lcov-file: ./coverage/lcov.info
                   github-token: ${{ secrets.GITHUB_TOKEN }}