feat: add mac-optimizer skill (92) — Claude Code only

macOS system health toolkit with 5 audit modules (packages, environment,
security, cleanup, resources) and cleanup executor. Fixed bugs from review:
- Replace GNU timeout with perl alarm (macOS compatible)
- Remove Linux-only ps --sort flag, use portable sort
- Add JSON escaping to all audit scripts
- Remove redundant classify_size branch

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

README.md

@@ -2,7 +2,7 @@
 
 > **Internal R&D Repository** - This repository is restricted for internal use only.
 
-A collection of **61 custom Claude Skills** for OurDigital workflows, D.intelligence Agent Corps (9-agent business operations suite), Jamie Plastic Surgery Clinic brand management, SEO/GTM tools, NotebookLM automation, Notion integrations, reference documentation curation, and multi-agent collaboration.
+A collection of **62 custom Claude Skills** for OurDigital workflows, D.intelligence Agent Corps (9-agent business operations suite), Jamie Plastic Surgery Clinic brand management, SEO/GTM tools, NotebookLM automation, Notion integrations, reference documentation curation, macOS system optimization, and multi-agent collaboration.
 
 ## Quick Install
 
@@ -121,7 +121,13 @@ cd our-claude-skills/custom-skills/_ourdigital-shared
 
 **Prerequisites:** `pip install notebooklm-py && playwright install chromium && notebooklm login`
 
-### Reference Curator & Multi-Agent (90-99)
+### System Tools (92)
+
+| # | Skill | Purpose |
+|---|-------|---------|
+| 92 | `mac-optimizer` | macOS system health audit & optimization (Claude Code only) |
+
+### Reference Curator & Multi-Agent (90-91)
 
 | # | Skill | Purpose |
 |---|-------|---------|
@@ -177,6 +183,7 @@ our-claude-skills/
 │   ├── 50-53 (NotebookLM tools)
 │   ├── 90-reference-curator/
 │   ├── 91-multi-agent-guide/
+│   ├── 92-mac-optimizer/
 │   └── 99_archive/
 │
 ├── example-skills/              # Anthropic reference examples