feat: Add OurDigital custom skills package (10 skills)

Complete implementation of OurDigital skills with dual-platform support
(Claude Desktop + Claude Code) following standardized structure.

Skills created:
- 01-ourdigital-brand-guide: Brand reference & style guidelines
- 02-ourdigital-blog: Korean blog drafts (blog.ourdigital.org)
- 03-ourdigital-journal: English essays (journal.ourdigital.org)
- 04-ourdigital-research: Research prompts & workflows
- 05-ourdigital-document: Notion-to-presentation pipeline
- 06-ourdigital-designer: Visual/image prompt generation
- 07-ourdigital-ad-manager: Ad copywriting & keyword research
- 08-ourdigital-trainer: Training materials & workshop planning
- 09-ourdigital-backoffice: Quotes, proposals, cost analysis
- 10-ourdigital-skill-creator: Meta skill for creating new skills

Features:
- YAML frontmatter with "ourdigital" or "our" prefix triggers
- Standardized directory structure (code/, desktop/, shared/, docs/)
- Shared environment setup (_ourdigital-shared/)
- Comprehensive reference documentation
- Cross-skill integration support

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

custom-skills/07-ourdigital-ad-manager/README.md

@@ -0,0 +1,81 @@
+# OurDigital Ad Manager
+
+Ad copywriting and keyword research for OurDigital marketing campaigns.
+
+## Purpose
+
+Create compelling advertising content:
+- Search ad copy (Google, Naver)
+- Display ad copy
+- Branded content
+- Keyword research and analysis
+
+## Activation
+
+Only activates with "ourdigital" keyword:
+- "ourdigital ad copy for [product]"
+- "ourdigital 광고 카피 작성해줘"
+- "ourdigital keyword research"
+
+## Features
+
+### Search Ad Copy
+- Google Ads format (30×3 headlines, 90×2 descriptions)
+- Naver Search Ad format (25자 제목, 45자 설명)
+- Keyword-optimized headlines
+- A/B test variations
+
+### Display Ad Copy
+- Leaderboard, rectangle, responsive formats
+- Problem-solution-CTA formula
+- Visual-copy synchronization
+
+### Keyword Research
+- Search volume analysis
+- Intent mapping (informational → transactional)
+- Competitor keyword analysis
+- Long-tail opportunities
+
+## Structure
+
+```
+07-ourdigital-ad-manager/
+├── code/
+│   ├── SKILL.md
+│   └── scripts/
+│       ├── generate_ads.py
+│       ├── keyword_research.py
+│       └── ad_analyzer.py
+├── desktop/
+│   ├── SKILL.md
+│   └── skill.yaml
+├── shared/
+│   └── references/
+│       ├── ad-copy-formulas.md
+│       └── platform-specs.md
+├── docs/
+│   └── CHANGELOG.md
+└── README.md
+```
+
+## Platform Support
+
+| Platform | Format | Focus |
+|----------|--------|-------|
+| Google Ads | 30×3 + 90×2 | Keyword match |
+| Naver | 25 + 45 | Trust signals |
+| Meta | 40 + 125 | Visual sync |
+| LinkedIn | 150 + 70 | Professional |
+
+## Integration
+
+Works with:
+- `01-ourdigital-brand-guide` - Brand voice
+- `04-ourdigital-research` - Market research
+- Google Ads Editor
+- Naver 검색광고
+
+## Version
+
+- Current: 1.0.0
+- Author: OurDigital