test(integration): Add 10 integration tests for annotation endpoints + update docs
Integration tests:
- 5 happy path tests (TextMarkup, FreeText, StickyNote, Circle, Square) with multipart + Base64 mix
- 5 validation error tests (invalid Base64, page number, missing content/style, invalid color)
- All existing 7 merge tests retained (now 17 total in PdfOperationsControllerTests)
Documentation updates (AGENTS.md):
- Update test count: 82 -> 101 passed, 7 skipped
- Update PdfOperationsController status: 1/N -> 2/3 endpoints (merge + annotate DONE, stamp TODO)
- Add test breakdown by feature (6 features listed)
- Update 'Run tests' section with Feature 6 mention
Test results: 101 PASSED, 7 SKIPPED, 0 FAILED
TekH
d72d41ec2d