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/74-dintel-service-architect/code/CLAUDE.md

@@ -9,7 +9,7 @@ Design service scope and recommend optimal module combinations for client needs.
 - **Agent #74** -- Service Architect
 - **Upstream**: Agent #77 (Account Manager) provides client intake
 - **Downstream**: Agent #73 (Quotation Manager) receives structured scope for pricing
-- **Shared constants**: `dintel-shared/src/dintel/brand.py` (colors, terminology, style tokens)
+- **Shared constants**: `_dintel-shared/src/dintel/brand.py` (colors, terminology, style tokens)
 
 ## Universal Guardrails
 
@@ -27,7 +27,7 @@ Design service scope and recommend optimal module combinations for client needs.
 - **Concept**: SMART Marketing Clinic
 - **Tagline**: Analysis, Treatment & Growth
 - **Decision Tree**: `../shared/module-decision-tree.md`
-- **Brand constants**: `../../dintel-shared/src/dintel/brand.py`
+- **Brand constants**: `../../_dintel-shared/src/dintel/brand.py`
 
 ## Service Module Source Data