feat: add 33 skills from vudovn/antigravity-kit

- Added: api-patterns, app-builder, architecture, bash-linux, behavioral-modes,
  clean-code, code-review-checklist, database-design, deployment-procedures,
  docker-expert, documentation-templates, game-development, geo-fundamentals,
  i18n-localization, lint-and-validate, mobile-design, nestjs-expert,
  nextjs-best-practices, nodejs-best-practices, parallel-agents,
  performance-profiling, plan-writing, powershell-windows, prisma-expert,
  python-patterns, react-patterns, red-team-tactics, seo-fundamentals,
  server-management, tailwind-patterns, tdd-workflow, typescript-expert,
  vulnerability-scanner
- Updated README: skill count 179 → 223
- Added credit for vudovn/antigravity-kit (MIT License)

Source: https://github.com/vudovn/antigravity-kit

skills/game-development/mobile-games/SKILL.md

@@ -0,0 +1,108 @@
+---
+name: mobile-games
+description: Mobile game development principles. Touch input, battery, performance, app stores.
+allowed-tools: Read, Write, Edit, Glob, Grep
+---
+
+# Mobile Game Development
+
+> Platform constraints and optimization principles.
+
+---
+
+## 1. Platform Considerations
+
+### Key Constraints
+
+| Constraint | Strategy |
+|------------|----------|
+| **Touch input** | Large hit areas, gestures |
+| **Battery** | Limit CPU/GPU usage |
+| **Thermal** | Throttle when hot |
+| **Screen size** | Responsive UI |
+| **Interruptions** | Pause on background |
+
+---
+
+## 2. Touch Input Principles
+
+### Touch vs Controller
+
+| Touch | Desktop/Console |
+|-------|-----------------|
+| Imprecise | Precise |
+| Occludes screen | No occlusion |
+| Limited buttons | Many buttons |
+| Gestures available | Buttons/sticks |
+
+### Best Practices
+
+- Minimum touch target: 44x44 points
+- Visual feedback on touch
+- Avoid precise timing requirements
+- Support both portrait and landscape
+
+---
+
+## 3. Performance Targets
+
+### Thermal Management
+
+| Action | Trigger |
+|--------|---------|
+| Reduce quality | Device warm |
+| Limit FPS | Device hot |
+| Pause effects | Critical temp |
+
+### Battery Optimization
+
+- 30 FPS often sufficient
+- Sleep when paused
+- Minimize GPS/network
+- Dark mode saves OLED battery
+
+---
+
+## 4. App Store Requirements
+
+### iOS (App Store)
+
+| Requirement | Note |
+|-------------|------|
+| Privacy labels | Required |
+| Account deletion | If account creation exists |
+| Screenshots | For all device sizes |
+
+### Android (Google Play)
+
+| Requirement | Note |
+|-------------|------|
+| Target API | Current year's SDK |
+| 64-bit | Required |
+| App bundles | Recommended |
+
+---
+
+## 5. Monetization Models
+
+| Model | Best For |
+|-------|----------|
+| **Premium** | Quality games, loyal audience |
+| **Free + IAP** | Casual, progression-based |
+| **Ads** | Hyper-casual, high volume |
+| **Subscription** | Content updates, multiplayer |
+
+---
+
+## 6. Anti-Patterns
+
+| ❌ Don't | ✅ Do |
+|----------|-------|
+| Desktop controls on mobile | Design for touch |
+| Ignore battery drain | Monitor thermals |
+| Force landscape | Support player preference |
+| Always-on network | Cache and sync |
+
+---
+
+> **Remember:** Mobile is the most constrained platform. Respect battery and attention.