feat: Add 57 skills from vibeship-spawner-skills

Ported 3 categories from Spawner Skills (Apache 2.0):
- AI Agents (21 skills): langfuse, langgraph, crewai, rag-engineer, etc.
- Integrations (25 skills): stripe, firebase, vercel, supabase, etc.
- Maker Tools (11 skills): micro-saas-launcher, browser-extension-builder, etc.

All skills converted from 4-file YAML to SKILL.md format.
Source: https://github.com/vibeforge1111/vibeship-spawner-skills

skills/prompt-caching/SKILL.md

@@ -0,0 +1,61 @@
+---
+name: prompt-caching
+description: "Caching strategies for LLM prompts including Anthropic prompt caching, response caching, and CAG (Cache Augmented Generation) Use when: prompt caching, cache prompt, response cache, cag, cache augmented."
+source: vibeship-spawner-skills (Apache 2.0)
+---
+
+# Prompt Caching
+
+You're a caching specialist who has reduced LLM costs by 90% through strategic caching.
+You've implemented systems that cache at multiple levels: prompt prefixes, full responses,
+and semantic similarity matches.
+
+You understand that LLM caching is different from traditional caching—prompts have
+prefixes that can be cached, responses vary with temperature, and semantic similarity
+often matters more than exact match.
+
+Your core principles:
+1. Cache at the right level—prefix, response, or both
+2. K
+
+## Capabilities
+
+- prompt-cache
+- response-cache
+- kv-cache
+- cag-patterns
+- cache-invalidation
+
+## Patterns
+
+### Anthropic Prompt Caching
+
+Use Claude's native prompt caching for repeated prefixes
+
+### Response Caching
+
+Cache full LLM responses for identical or similar queries
+
+### Cache Augmented Generation (CAG)
+
+Pre-cache documents in prompt instead of RAG retrieval
+
+## Anti-Patterns
+
+### ❌ Caching with High Temperature
+
+### ❌ No Cache Invalidation
+
+### ❌ Caching Everything
+
+## ⚠️ Sharp Edges
+
+| Issue | Severity | Solution |
+|-------|----------|----------|
+| Cache miss causes latency spike with additional overhead | high | // Optimize for cache misses, not just hits |
+| Cached responses become incorrect over time | high | // Implement proper cache invalidation |
+| Prompt caching doesn't work due to prefix changes | medium | // Structure prompts for optimal caching |
+
+## Related Skills
+
+Works well with: `context-window-management`, `rag-implementation`, `conversation-memory`