refactor: reorganize skill numbering, remove obsolete skills, rename shared libs

- Rename: 00→80 claude-settings-optimizer, 88→79 dintel-skill-update,
  92→81 mac-optimizer, 93→82 tui-design-template
- Rename: dintel-shared → _dintel-shared (consistent with _ourdigital-shared)
- Remove: 61-gtm-manager, 62-gtm-guardian (obsolete), 99_archive
- Update all dintel-* skill refs (114 occurrences across 31 files)
- Sync README.md, CLAUDE.md, AGENTS.md with new structure

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

custom-skills/76-dintel-backoffice-mgr/README.md

@@ -44,7 +44,7 @@ Back Office & HR Manager -- handles administrative operations, invoicing, contra
 - Document Templates: `/Users/ourdigital/Documents/D.intelligence Service Package/Source Files/문서 양식/`
 - Service Map: `/Users/ourdigital/Documents/D.intelligence Service Package/00_SERVICE-MAP.md`
 - Pricing Packages: `/Users/ourdigital/Documents/D.intelligence Service Package/06_PRICING-PACKAGES.md`
-- Shared Utilities: `../../dintel-shared/src/dintel/`
+- Shared Utilities: `../../_dintel-shared/src/dintel/`
 
 ## Workflow Chain
 

custom-skills/76-dintel-backoffice-mgr/code/CLAUDE.md

@@ -24,7 +24,7 @@ from dintel.document import create_branded_doc, save_doc
 from dintel.notion import DB_TASKS_DASHBOARD, CLIENT_DB_MAP
 ```
 
-- **dintel-shared** path: `../dintel-shared/src/dintel/`
+- **_dintel-shared** path: `../_dintel-shared/src/dintel/`
 - `document.py` -- DOCX generation with brand styles
 - `brand.py` -- Brand constants, colors, prohibited words
 - `notion.py` -- Notion DB IDs, client mappings