feat(skills): bulk-add root SKILL.md to 61 skills (native Agent Skills loadability)

Run the additive migration pass from SKILL-MIGRATION-GUIDE: generate a root SKILL.md
for every skill that lacked one, copied from its desktop/SKILL.md (or code/SKILL.md),
with name set to the directory name and description + body preserved verbatim.

- scripts/migrate_skill_root.py: the reusable, non-destructive migrator (dry-run default).
- 61 new root SKILL.md (desktop source for most; code/SKILL.md for 61/62/92).
- Untouched: 16/17/95 (already had root); desktop/ and code/ packaging left intact.
- All 64 root SKILL.md validate: frontmatter <=1024, kebab name, description present.

Still MANUAL (no SKILL.md source — commands/README only), need hand-authored root SKILL.md:
81-mac-optimizer, 90-reference-curator, 91-multi-agent-guide, 94-dintel-bootstrap.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

custom-skills/06-ourdigital-designer/SKILL.md

@@ -0,0 +1,145 @@
+---
+name: 06-ourdigital-designer
+description: |
+  Visual storytelling and image prompt generation for OurDigital.
+  Activated with "ourdigital" keyword for design tasks.
+
+  Triggers (ourdigital or our prefix):
+  - "ourdigital design", "our design"
+  - "ourdigital 디자인", "our 디자인"
+  - "ourdigital image prompt", "our image prompt"
+  - "ourdigital 썸네일", "our 썸네일"
+
+  Features:
+  - Philosophical visual narrative creation
+  - Image prompt generation for AI art tools
+  - Korean-Western aesthetic fusion
+  - Blog featured image optimization
+version: "1.1"
+author: OurDigital
+environment: Desktop
+---
+
+# OurDigital Designer
+
+Transform philosophical essays into sophisticated visual narratives through minimalist, conceptually rich featured images.
+
+## Activation
+
+Activate with "ourdigital" or "our" prefix:
+- "ourdigital design" / "our design"
+- "ourdigital 썸네일" / "our 썸네일"
+- "our image prompt for [topic]"
+
+## Core Philosophy
+
+OurDigital images are visual philosophy—not illustrations but parallel texts that invite contemplation. Each image captures the essay's philosophical core through:
+
+- **Abstract metaphors** over literal representations
+- **Contemplative minimalism** with 20%+ negative space
+- **Cultural fusion** of Korean-Western aesthetics
+- **Emotional resonance** through color psychology
+
+## Workflow
+
+### Phase 1: Extract Essay Essence
+
+Analyze the content for:
+- **Core insight**: What philosophical truth?
+- **Emotional tone**: What feeling to evoke?
+- **Key metaphor**: What visual symbol?
+
+### Phase 2: Select Visual Approach
+
+| Essay Type | Visual Strategy | Color Mood |
+|-----------|-----------------|------------|
+| Technology | Organic-digital hybrids | Cool blues → warm accents |
+| Social | Network patterns, human fragments | Desaturated → hope spots |
+| Philosophy | Zen space, symbolic objects | Monochrome + single accent |
+| Cultural | Layered traditions, fusion forms | Earth tones → modern hues |
+
+### Phase 3: Generate Prompt
+
+Build structured prompt with:
+```
+[Style] + [Subject] + [Composition] + [Color] + [Technical specs]
+```
+
+### Phase 4: Quality Check
+
+✅ **Must have:**
+- Captures philosophical insight
+- Works at 200px thumbnail
+- Timeless (2-3 year relevance)
+- Cross-cultural readability
+
+❌ **Must avoid:**
+- Tech clichés (circuits, binary)
+- Stock photo aesthetics
+- Literal interpretations
+- Trendy effects
+
+## Quick Templates
+
+### AI & Humanity
+```
+"Translucent human silhouette dissolving into crystalline data structures.
+Monochrome with teal accent. Boundary dissolution between organic/digital.
+1200x630px, minimalist vector style."
+```
+
+### Social Commentary
+```
+"Overlapping circles forming maze pattern, tiny humans in separate chambers.
+Blue-gray palette, warm light leaks for hope. Subtle Korean patterns.
+High negative space. 1200x630px."
+```
+
+### Digital Transformation
+```
+"Traditional forms metamorphosing into particle streams. Paper texture → digital grain.
+Earth tones shifting to cool blues. Sacred geometry underlying.
+1200x630px, contemplative mood."
+```
+
+## Visual Metaphor Shortcuts
+
+| Concept | Visual Metaphor |
+|---------|-----------------|
+| Algorithm | Constellation patterns |
+| Identity | Layered masks, fingerprints |
+| Network | Root systems, neural paths |
+| Time | Spirals, sediment layers |
+| Knowledge | Light sources, growing trees |
+
+## Color Psychology
+
+| Mood | Palette |
+|------|---------|
+| Critical | Deep blue-gray + red accent |
+| Hopeful | Warm amber + sky blue |
+| Philosophical | Near black + off white + gold |
+| Anxious | Charcoal + grey-blue + digital green |
+
+## Technical Specs
+
+- **Dimensions**: 1200x630px (OG standard)
+- **Style**: Vector illustration + subtle textures
+- **Colors**: 60-30-10 rule (dominant-secondary-accent)
+- **Format**: WebP primary, JPG fallback
+
+## Quick Commands
+
+| Command | Action |
+|---------|--------|
+| "ourdigital design [topic]" | Generate image prompt |
+| "ourdigital 썸네일 [주제]" | Korean trigger |
+| "ourdigital visual → midjourney" | MidJourney optimized |
+| "ourdigital visual → dalle" | DALL-E optimized |
+
+## References
+
+- `shared/references/visual-metaphors.md` - Concept dictionary
+- `shared/references/color-palettes.md` - Emotion → color mapping
+- `shared/references/advanced-techniques.md` - Complex compositions
+- `01-ourdigital-brand-guide` - Brand visual identity