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/plaid-fintech/SKILL.md

@@ -0,0 +1,50 @@
+---
+name: plaid-fintech
+description: "Expert patterns for Plaid API integration including Link token flows, transactions sync, identity verification, Auth for ACH, balance checks, webhook handling, and fintech compliance best practices. Use when: plaid, bank account linking, bank connection, ach, account aggregation."
+source: vibeship-spawner-skills (Apache 2.0)
+---
+
+# Plaid Fintech
+
+## Patterns
+
+### Link Token Creation and Exchange
+
+Create a link_token for Plaid Link, exchange public_token for access_token.
+Link tokens are short-lived, one-time use. Access tokens don't expire but
+may need updating when users change passwords.
+
+
+### Transactions Sync
+
+Use /transactions/sync for incremental transaction updates. More efficient
+than /transactions/get. Handle webhooks for real-time updates instead of
+polling.
+
+
+### Item Error Handling and Update Mode
+
+Handle ITEM_LOGIN_REQUIRED errors by putting users through Link update mode.
+Listen for PENDING_DISCONNECT webhook to proactively prompt users.
+
+
+## Anti-Patterns
+
+### ❌ Storing Access Tokens in Plain Text
+
+### ❌ Polling Instead of Webhooks
+
+### ❌ Ignoring Item Errors
+
+## ⚠️ Sharp Edges
+
+| Issue | Severity | Solution |
+|-------|----------|----------|
+| Issue | critical | See docs |
+| Issue | high | See docs |
+| Issue | high | See docs |
+| Issue | high | See docs |
+| Issue | medium | See docs |
+| Issue | medium | See docs |
+| Issue | medium | See docs |
+| Issue | medium | See docs |