docs: update guide content, examples, tools, and reference files

- guide/ultimate-guide.md — content updates
- guide/workflows/README.md, guide/README.md — navigation improvements
- guide/diagrams/ — diagram updates (context/sessions, config, MCP ecosystem)
- guide/third-party-tools.md — additions
- examples/README.md, hooks/README.md, scripts/README.md — examples updates
- examples/skills/pr-triage/SKILL.md — expanded skill
- machine-readable/reference.yaml — reference sync
- tools/audit-prompt.md, tools/onboarding-prompt.md — tooling updates
- docs/for-cto.md, docs/for-tech-leads.md, docs/resource-evaluations/README.md — doc updates
- .gitignore — gitignore update

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

.gitignore

@@ -32,6 +32,7 @@ __pycache__/
 
 # Personal notes & temp files
 to-ignore/
+docs/drafts/
 .grepai/
 whitepapers/
 claudedocs/