Implement onboarding reset functionality and enhance backup features

- Added a new method to reset the onboarding state, allowing users to re-initiate the onboarding process.
- Integrated backup creation functionality, enabling users to create encrypted backups of their node identity.
- Updated API endpoints to handle onboarding reset and backup creation requests.
- Enhanced UI components to support the new onboarding reset and backup features, including error handling and user feedback.
- Introduced new dependencies for cryptographic operations and data encoding.

neode-ui/src/api/rpc-client.ts

@@ -135,6 +135,13 @@ class RPCClient {
     })
   }
 
+  async resetOnboarding(): Promise<boolean> {
+    return this.call({
+      method: 'auth.resetOnboarding',
+      params: {},
+    })
+  }
+
   async getNodeDid(): Promise<{ did: string; pubkey: string }> {
     return this.call({
       method: 'node.did',
@@ -142,6 +149,28 @@ class RPCClient {
     })
   }
 
+  async signChallenge(challenge: string): Promise<{ signature: string }> {
+    return this.call({
+      method: 'node.signChallenge',
+      params: { challenge },
+    })
+  }
+
+  async createBackup(passphrase: string): Promise<{
+    version: number
+    did: string
+    pubkey: string
+    kid: string
+    encrypted: boolean
+    blob: string
+    timestamp: string
+  }> {
+    return this.call({
+      method: 'node.createBackup',
+      params: { passphrase },
+    })
+  }
+
   async publishNostrIdentity(): Promise<{ event_id: string; success: number; failed: number }> {
     return this.call({
       method: 'node.nostr-publish',