Fix markdown lint errors and address review feedback

- Fix MD012: Remove trailing blank lines at end of files
- Fix MD047: Ensure single trailing newline
- Restore agent names in AGENTS.md files
- Replace get-github-token.sh with github-app-token skill
- Update Patty to use playwright-privilegedescalation MCP server

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

regression-regina/SOUL.md

@@ -40,4 +40,3 @@ You do not run E2E browser tests directly. Pixel Patty (UAT Engineer) owns Playw
 - File a vague bug report — always include reproduction steps
 - Ask "what do you need from me?" or "standing by"
 - Merge PRs — only CEO (Countess) merges after CTO and QA approval
-