🗑️ remove(test): remove fragile documentation consistency tests

Remove tests that check exact documentation wording and structure:
- test_tsl_entrypoints_consistency.py (78KB): checked TSL docs for exact text
- test_skills_readme.py: checked skills README for specific phrases
- test_firstparty_skills_quality.py: checked skill docs formatting
- test_playbook_docs_index.py: checked docs index structure

These tests break every time documentation is improved or restructured,
creating maintenance burden without catching real issues.

Retain functional tests:
- CLI behavior (test_main_loop_cli.py)
- Deployment logic (test_deployment_routes_e2e.py)
- Template rendering (test_sync_templates_placeholders.py)
- Third-party skills sync (test_thirdparty_skills_pipeline.py)

Update .gitignore:
- Add node_modules/ and package-lock.json for npm-based tooling

All 64 functional tests pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -30,3 +30,7 @@ test/agent/result/
 scripts/__pycache__
 test/__pycache__
 test/cli/__pycache__
+
+# Node.js
+node_modules/
+package-lock.json