Fix CI failures: labeler schema, module masking, and artifacts

- Updated .github/labeler.yml to the correct actions/labeler@v5 format.
- Renamed 'yaml' file to 'gh-workflow-sample.yaml' to resolve 'yaml' module import conflict.
- Added 'pyyaml' and 'jsonschema' to requirements-governance-checks.txt.
- Updated .gitignore to exclude operational artifacts (worm_batch_*.json, monitor.log).
- Refactored tools/validate_governance_artifacts.py and scripts for linting/parity.

Co-authored-by: OneFineStarstuff <87420139+OneFineStarstuff@users.noreply.github.com>

Author: google-labs-jules[bot]

.github/labeler.yml

@@ -1,11 +1,17 @@
 backend:
-  - 'backend/**/*'
+  - changed-files:
+      - any-glob-to-any-file: 'backend/**/*'
 frontend:
-  - 'frontend/**/*'
+  - changed-files:
+      - any-glob-to-any-file: 'frontend/**/*'
 next-app:
-  - 'next-app/**/*'
+  - changed-files:
+      - any-glob-to-any-file: 'next-app/**/*'
 documentation:
-  - 'docs/**/*'
-  - '**/*.md'
+  - changed-files:
+      - any-glob-to-any-file:
+          - 'docs/**/*'
+          - '**/*.md'
 python:
-  - '**/*.py'
+  - changed-files:
+      - any-glob-to-any-file: '**/*.py'

.gitignore

@@ -42,3 +42,7 @@ __pycache__/
 artifacts/test-results/
 governance-artifact-validation-report.json
 governance-validation-suite-report.json
+
+# Operational artifacts
+worm_batch_*.json
+monitor.log