Add SEO skills 19-28, 31-32 with full Python implementations

12 new skills: Keyword Strategy, SERP Analysis, Position Tracking,
Link Building, Content Strategy, E-Commerce SEO, KPI Framework,
International SEO, AI Visibility, Knowledge Graph, Competitor Intel,
and Crawl Budget. ~20K lines of Python across 25 domain scripts.
Updated skill 11 pipeline table and repo CLAUDE.md.
Enhanced skill 18 local SEO workflow from jamie.clinic audit.

Note: Skill 26 hreflang_validator.py pending (content filter block).

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

custom-skills/26-seo-international/code/scripts/requirements.txt

@@ -0,0 +1,10 @@
+# 26-seo-international dependencies
+requests>=2.31.0
+aiohttp>=3.9.0
+beautifulsoup4>=4.12.0
+lxml>=5.1.0
+langdetect>=1.0.9
+tenacity>=8.2.0
+tqdm>=4.66.0
+python-dotenv>=1.0.0
+rich>=13.7.0