Restructure skill numbering: SEO 11-30, GTM 60-69, reserve 19-28 for future skills

Renumber 12 existing skills to new ranges:
- SEO: 11→13, 12→18, 13→16, 14→17, 15→14, 16→15, 17→29, 18→30, 19→12
- GTM: 20→60, 21→61, 22→62

Update cross-references in gateway architect/builder skills, GTM guardian
README, CLAUDE.md (skill tables + directory layout), and AGENTS.md
(domain routing ranges).

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

custom-skills/29-seo-gateway-architect/code/scripts/requirements.txt

@@ -0,0 +1,25 @@
+# Python dependencies for SEO Gateway Page Strategist scripts
+# Install with: pip install -r requirements.txt
+
+# Core dependencies
+requests>=2.28.0
+beautifulsoup4>=4.11.0
+pandas>=1.5.0
+numpy>=1.23.0
+
+# For API integrations (optional)
+google-api-python-client>=2.70.0
+pytrends>=4.9.0
+
+# For data visualization (optional)
+matplotlib>=3.6.0
+seaborn>=0.12.0
+
+# For export formats
+openpyxl>=3.0.0
+jinja2>=3.1.0
+
+# Development tools
+pytest>=7.2.0
+black>=22.0.0
+pylint>=2.15.0