release: v3.20.7 - Addy Osmani spec-writing integration

Version Bump:
- VERSION: 3.20.6 → 3.20.7
- CHANGELOG.md: New [3.20.7] section with Osmani integration details
- Synced across: README.md, cheatsheet.md, ultimate-guide.md, reference.yaml

Release Highlights:
- Addy Osmani spec-writing evaluation (4/5, High Value)
- 4 new sections in spec-first.md (Modular Design, Operational Boundaries, Command Templates, Anti-Monolithic)
- 180 lines added to spec-first.md (327 → 507)
- 8 new reference.yaml entries
- 1 new resource evaluation (36 total)

Integration Details (see CHANGELOG.md):
- Modular spec design pattern (split >200 line CLAUDE.md files)
- Always/Ask First/Never operational boundaries framework
- Command spec templates with error handling
- Anti-pattern: monolithic CLAUDE.md context pollution

Landing Sync: Ready for deployment (version updated in separate commit)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

guide/ultimate-guide.md

@@ -10,7 +10,7 @@
 
 **Last updated**: January 2026
 
-**Version**: 3.20.6
+**Version**: 3.20.7
 
 ---
 
@@ -1864,6 +1864,8 @@ ccusage --model-breakdown  # Cost by model (Sonnet/Opus/Haiku)
 - **Budget planning**: Set monthly spending targets
 - **Team analytics**: Aggregate costs across developers
 
+> For a full inventory of community cost trackers, session viewers, config managers, and alternative UIs, see [Third-Party Tools](./third-party-tools.md).
+
 **Monthly tracking**:
 
 Check your Anthropic Console for detailed usage:
@@ -16410,4 +16412,4 @@ We'll evaluate and add it to this section if it meets quality criteria.
 
 **Contributions**: Issues and PRs welcome.
 
-**Last updated**: January 2026 | **Version**: 3.20.6
+**Last updated**: January 2026 | **Version**: 3.20.7