docs: update stale version numbers, MCP counts, and test counts across docs/

Version headers/footers updated to 3.1.0-dev:
- docs/features/BOOTSTRAP_SKILL_TECHNICAL.md (was 2.8.0-dev)
- docs/reference/API_REFERENCE.md (was 2.7.0)
- docs/reference/CODE_QUALITY.md (was 2.7.0)
- docs/guides/TESTING_GUIDE.md (was 2.7.0)
- docs/guides/MIGRATION_GUIDE.md (was 2.7.0, historical tables untouched)

MCP tool count 18 → 26:
- docs/guides/MCP_SETUP.md
- docs/guides/TESTING_GUIDE.md
- docs/reference/CODE_QUALITY.md
- docs/reference/CLAUDE_INTEGRATION.md
- docs/integrations/CLINE.md
- docs/strategy/INTEGRATION_STRATEGY.md

Test count 700+/1200+ → 1,880+:
- docs/guides/MCP_SETUP.md
- docs/guides/TESTING_GUIDE.md
- docs/reference/CODE_QUALITY.md
- docs/reference/CLAUDE_INTEGRATION.md
- docs/features/HOW_TO_GUIDES.md
- docs/blog/UNIVERSAL_RAG_PREPROCESSOR.md

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

docs/strategy/INTEGRATION_STRATEGY.md

@@ -30,7 +30,7 @@ We can replicate this positioning with dozens of other tools/platforms to create
 | Aspect | Their Use | Our Capability | Gap |
 |--------|-----------|---------------|-----|
 | **GitHub scraping** | ✅ Basic | ✅ Advanced (C3.x) | **Large** |
-| **MCP integration** | ✅ Aware | ✅ 18 tools available | **Medium** |
+| **MCP integration** | ✅ Aware | ✅ 26 tools available | **Medium** |
 | **Context limits** | ⚠️ Problem | ✅ Router skills solve | **Large** |
 | **AI enhancement** | ❌ Not mentioned | ✅ Dual mode (API/LOCAL) | **Large** |
 | **Multi-platform** | ❌ Claude only | ✅ 4 platforms | **Medium** |