GRM-132: ci: bump devx to 0.33.0, use devx-check-api-identity-checks

.devin/skills/testing-and-debugging/SKILL.md

@@ -69,3 +69,24 @@ source activate.zsh      # zsh
 ```
 
 If `.venv` doesn't exist, run `make setup` first.
+
+## Common Pitfalls
+
+### Coverage Verification Before Push
+
+**Always run `make pytest-cov` before pushing** — CI enforces 100%
+coverage and will fail the PR if any lines are uncovered. This is the
+most common cause of CI quality job failures after code changes. The
+pre-push git hook only validates Vikunja task existence, not tests.
+
+### API Response Type Checking
+
+Never use `is True`/`is False` identity checks on API response values.
+Many APIs return boolean values as strings (`"true"`/`"false"`). Use
+string comparison or truthy/falsy helpers instead.
+
+### Time Mocking in Tests
+
+Always mock `time.sleep` and `time.monotonic` in unit tests using
+`@patch` decorators. Real sleep calls make tests slow and exceed test
+speed limits.