**Motivations:**
- Provide clearer error messages when NIP-98 authentication is not available
- Disable nostrimg.com by default since it returns server errors (500)
- Help users understand why nostrcheck.me endpoint is skipped
**Root causes:**
- NIP-98 authentication requires unlocked account but error message was generic
- nostrimg.com endpoint consistently returns 500 errors
- Users don't understand why nostrcheck.me is skipped
**Correctifs:**
- Added detailed error messages for NIP-98 unavailability:
- No account: 'Please create or import an account'
- Account not unlocked: 'Please unlock your account with your recovery phrase'
- Disabled nostrimg.com by default (enabled: false) due to server errors
- Improved console warnings with specific reasons for skipping endpoints
**Evolutions:**
- None
**Pages affectées:**
- lib/nip95.ts
- lib/configStorageTypes.ts
- Add NEXT_PUBLIC_NIP95_UPLOAD_URL to README environment variables section
- Add NIP-95 upload service documentation with examples
- Create .env.example file with all required environment variables
- Improve error message to guide users to README for setup instructions
- All TypeScript checks pass