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/23-seo-content-strategy/code/CLAUDE.md

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+# CLAUDE.md
+
+## Overview
+
+Content strategy tool for SEO-driven content planning. Performs content inventory via sitemap crawl and Ahrefs top pages, scores content performance, detects content decay, analyzes topic gaps vs competitors, maps topic clusters, and generates content briefs. Supports Korean content patterns (Naver Blog format, review/후기 content).
+
+## Quick Start
+
+```bash
+pip install -r scripts/requirements.txt
+
+# Content audit
+python scripts/content_auditor.py --url https://example.com --json
+
+# Content gap analysis
+python scripts/content_gap_analyzer.py --target https://example.com --competitor https://competitor.com --json
+
+# Generate content brief
+python scripts/content_brief_generator.py --keyword "치과 임플란트 비용" --url https://example.com --json
+```
+
+## Scripts
+
+| Script | Purpose | Key Output |
+|--------|---------|------------|
+| `content_auditor.py` | Content inventory, performance scoring, decay detection | Content inventory with scores and decay flags |
+| `content_gap_analyzer.py` | Topic gap analysis and cluster mapping vs competitors | Missing topics, cluster map, editorial calendar |
+| `content_brief_generator.py` | Generate SEO content briefs with outlines | Brief with outline, keywords, word count targets |
+| `base_client.py` | Shared utilities | RateLimiter, ConfigManager, BaseAsyncClient |
+
+## Content Auditor
+
+```bash
+# Full content audit
+python scripts/content_auditor.py --url https://example.com --json
+
+# Detect decaying content
+python scripts/content_auditor.py --url https://example.com --decay --json
+
+# Filter by content type
+python scripts/content_auditor.py --url https://example.com --type blog --json
+```
+
+**Capabilities**:
+- Content inventory via sitemap crawl + Ahrefs top-pages
+- Performance scoring (traffic, rankings, backlinks)
+- Content decay detection (pages losing traffic over time)
+- Content type classification (blog, product, service, landing, resource)
+- Word count and freshness assessment
+- Korean content format analysis (Naver Blog style, 후기/review content)
+
+## Content Gap Analyzer
+
+```bash
+# Gap analysis vs competitor
+python scripts/content_gap_analyzer.py --target https://example.com --competitor https://comp1.com --json
+
+# With topic cluster mapping
+python scripts/content_gap_analyzer.py --target https://example.com --competitor https://comp1.com --clusters --json
+```
+
+**Capabilities**:
+- Topic gap identification vs competitors
+- Topic cluster mapping (pillar + cluster pages)
+- Content freshness comparison
+- Content volume comparison
+- Editorial calendar generation with priority scoring
+- Korean content opportunity detection
+
+## Content Brief Generator
+
+```bash
+# Generate brief for keyword
+python scripts/content_brief_generator.py --keyword "치과 임플란트 비용" --url https://example.com --json
+
+# With competitor analysis
+python scripts/content_brief_generator.py --keyword "dental implant cost" --url https://example.com --competitors 5 --json
+```
+
+**Capabilities**:
+- Content outline generation with H2/H3 structure
+- Target keyword list (primary + secondary + LSI)
+- Word count recommendation based on top-ranking pages
+- Competitor content analysis (structure, word count, topics covered)
+- Internal linking suggestions
+- Korean content format recommendations
+
+## Ahrefs MCP Tools Used
+
+| Tool | Purpose |
+|------|---------|
+| `site-explorer-top-pages` | Get top performing pages |
+| `site-explorer-pages-by-traffic` | Pages ranked by organic traffic |
+| `site-explorer-organic-keywords` | Keywords per page |
+| `site-explorer-organic-competitors` | Find content competitors |
+| `site-explorer-best-by-external-links` | Best content by links |
+
+## Output Format
+
+```json
+{
+  "url": "https://example.com",
+  "content_inventory": {
+    "total_pages": 150,
+    "by_type": {"blog": 80, "product": 40, "service": 20, "other": 10},
+    "avg_performance_score": 45
+  },
+  "decaying_content": [...],
+  "top_performers": [...],
+  "gaps": [...],
+  "clusters": [...],
+  "timestamp": "2025-01-01T00:00:00"
+}
+```
+
+## Notion Output (Required)
+
+**IMPORTANT**: All audit reports MUST be saved to the OurDigital SEO Audit Log database.
+
+### Database Configuration
+
+| Field | Value |
+|-------|-------|
+| Database ID | `2c8581e5-8a1e-8035-880b-e38cefc2f3ef` |
+| URL | https://www.notion.so/dintelligence/2c8581e58a1e8035880be38cefc2f3ef |
+
+### Required Properties
+
+| Property | Type | Description |
+|----------|------|-------------|
+| Issue | Title | Report title (Korean + date) |
+| Site | URL | Audited website URL |
+| Category | Select | Content Strategy |
+| Priority | Select | Based on gap severity |
+| Found Date | Date | Audit date (YYYY-MM-DD) |
+| Audit ID | Rich Text | Format: CONTENT-YYYYMMDD-NNN |
+
+### Language Guidelines
+
+- Report content in Korean (한국어)
+- Keep technical English terms as-is
+- URLs and code remain unchanged