feat: Import 35+ skills, merge duplicates, add openclaw installer

Major updates:
- Added 35+ new skills from awesome-opencode-skills and antigravity repos
- Merged SEO skills into seo-master
- Merged architecture skills into architecture
- Merged security skills into security-auditor and security-coder
- Merged testing skills into testing-master and testing-patterns
- Merged pentesting skills into pentesting
- Renamed website-creator to thai-frontend-dev
- Replaced skill-creator with github version
- Removed Chutes references (use MiniMax API instead)
- Added install-openclaw-skills.sh for cross-platform installation
- Updated .env.example with MiniMax API credentials

skills/frontend-dev/references/asset-prompt-guide.md

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+# Prompt Engineering Guide
+
+## Image Prompts
+
+- Be specific about composition: "left-aligned subject with negative space on the right for text overlay"
+- Specify lighting: "soft studio lighting", "golden hour backlight", "flat diffused light"
+- Include style modifiers: "editorial photography", "3D render", "flat vector illustration"
+- Add technical specs: "4K resolution, sharp focus, shallow depth of field"
+- For web assets: always mention "clean background", "web-optimized", "high contrast for readability"
+- **NEVER** include text in image prompts unless explicitly requested — AI text rendering is unreliable
+
+## Video Prompts
+
+- Use MiniMax camera commands in brackets: `[Push in]`, `[Truck left]`, `[Tracking shot]`, etc.
+- Describe scene, subject, lighting, and mood — the API auto-optimizes prompts by default
+- For web backgrounds: keep 6s duration, add `[Static shot]` for stability
+- Max 2,000 characters
+
+## Audio / TTS
+
+- Specify genre, tempo (BPM), mood, and instruments
+- For background music: "no vocals, suitable for background, not distracting"
+- For sound effects: be extremely specific about the sound event
+- For TTS: choose voice matching content language and speaker gender
+
+## Preset Shortcuts
+
+| Shortcut | Spec |
+|----------|------|
+| `hero` | 16:9 (1280x720) image, cinematic, text-safe space |
+| `thumb` | 1:1 (1024x1024) image, centered subject |
+| `icon` | 1:1 (1024x1024), flat style, clean background |
+| `avatar` | 1:1 (1024x1024), portrait, circular crop ready |
+| `banner` | 21:9 (1344x576), OG/social banner |
+| `portrait` | 2:3 (832x1248), vertical portrait |
+| `mobile` | 9:16 (720x1280), mobile fullscreen |
+| `bg-video` | 768P, 6s, `[Static shot]`, MiniMax Hailuo-2.3 |
+| `video` | 768P, 6s, MiniMax Hailuo-2.3, prompt auto-optimized |
+| `video-hd` | 1080P, 6s, MiniMax Hailuo-2.3 |
+| `bgm` | 30s background music, no vocals, loopable |
+| `sfx` | Short sound effect, < 3s |
+| `tts` | Text-to-speech, MiniMax HD, MP3 |
+| `narration` | Expressive narration voice, MiniMax |