- Add NHTSA client for VIN decoding with caching and validation
- Add POST /api/vehicles/decode-vin endpoint with tier gating
- Add dropdown matching service with confidence levels
- Add decode button to VehicleForm with tier check
- Responsive layout: stacks on mobile, inline on desktop
- Only populate empty fields (preserve user input)
Backend:
- NHTSAClient with 5s timeout, VIN validation, vin_cache table
- Tier gating with 'vehicle.vinDecode' feature key (Pro+)
- Tiered matching: high (exact), medium (normalized), none
Frontend:
- Decode button with loading state and error handling
- UpgradeRequiredDialog for free tier users
- Mobile-first responsive layout
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
