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/73-dintel-quotation-mgr/code/CLAUDE.md

@@ -8,8 +8,8 @@ Generate professional quotations and estimates for D.intelligence service module
 
 - **Agent #73** -- Quotation Manager (Multi-Agent)
 - **Collaborates with**: Agent #70 (Brand Guardian), Agent #71 (Brand Editor)
-- **Shared constants**: `dintel-shared/src/dintel/brand.py` (colors, terminology, style tokens)
-- **Excel utilities**: `dintel-shared/src/dintel/excel.py` (branded workbook generation)
+- **Shared constants**: `_dintel-shared/src/dintel/brand.py` (colors, terminology, style tokens)
+- **Excel utilities**: `_dintel-shared/src/dintel/excel.py` (branded workbook generation)
 
 ## Universal Guardrails
 
@@ -37,10 +37,10 @@ This agent generates quotation drafts and STOPS. It never finalizes or sends quo
 ## Quick Reference
 
 - **Full skill definition**: `../desktop/SKILL.md` (sub-agents, pricing tables, discount rules, output format)
-- **Pricing reference**: `../shared/pricing-reference.md` and `../../dintel-shared/references/pricing-reference.md`
+- **Pricing reference**: `../shared/pricing-reference.md` and `../../_dintel-shared/references/pricing-reference.md`
 - **Feedback log**: `../shared/feedback-log.md`
 - **Generate script**: `scripts/generate_quotation.py`
-- **Excel utilities**: `../../dintel-shared/src/dintel/excel.py`
+- **Excel utilities**: `../../_dintel-shared/src/dintel/excel.py`
 
 ## Quotation Template Library