Add NRC (Nostr Relay Connect) protocol and web UI (v0.48.9)

- Implement NIP-NRC protocol for remote relay access through public relay tunnel
- Add NRC bridge service with NIP-44 encrypted message tunneling
- Add NRC client library for applications
- Add session management with subscription tracking and expiry
- Add URI parsing for nostr+relayconnect:// scheme with secret and CAT auth
- Add NRC API endpoints for connection management (create/list/delete/get-uri)
- Add RelayConnectView.svelte component for managing NRC connections in web UI
- Add NRC database storage for connection secrets and labels
- Add NRC CLI commands (generate, list, revoke)
- Add support for Cashu Access Tokens (CAT) in NRC URIs
- Add ScopeNRC constant for Cashu token scope
- Add wasm build infrastructure and stub files

Files modified:
- app/config/config.go: NRC configuration options
- app/handle-nrc.go: New API handlers for NRC connections
- app/main.go: NRC bridge startup integration
- app/server.go: Register NRC API routes
- app/web/src/App.svelte: Add Relay Connect tab
- app/web/src/RelayConnectView.svelte: New NRC management component
- app/web/src/api.js: NRC API client functions
- main.go: NRC CLI command handlers
- pkg/bunker/acl_adapter.go: Add NRC scope mapping
- pkg/cashu/token/token.go: Add ScopeNRC constant
- pkg/database/nrc.go: NRC connection storage
- pkg/protocol/nrc/: New NRC protocol implementation
- docs/NIP-NRC.md: NIP specification document

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pkg/cashu/token/token.go

@@ -21,6 +21,7 @@ const (
 	ScopeNIP46   = "nip46"   // NIP-46 remote signing / bunker
 	ScopeBlossom = "blossom" // Blossom media server
 	ScopeAPI     = "api"     // HTTP API access
+	ScopeNRC     = "nrc"     // Nostr Relay Connect tunneling
 )
 
 // WildcardKind indicates all kinds are permitted.