feat: migrate NIP-51 list encryption from NIP-04 to NIP-44

NIP-04 encryption is deprecated due to security vulnerabilities.
This migrates MuteList (kind 10000) and PinnedUsers (kind 10010)
private entries to use NIP-44 encryption, with backward compatibility
for reading existing NIP-04 encrypted content. When NIP-04 content
is detected, it is automatically re-encrypted with NIP-44 and
republished to gradually migrate users.

Co-Authored-By: captain-stacks <201298974+captain-stacks@users.noreply.github.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/providers/NostrProvider/npub.signer.ts

@@ -31,4 +31,12 @@ export class NpubSigner implements ISigner {
   async nip04Decrypt(): Promise<any> {
     throw new Error('Not logged in')
   }
+
+  async nip44Encrypt(): Promise<any> {
+    throw new Error('Not logged in')
+  }
+
+  async nip44Decrypt(): Promise<any> {
+    throw new Error('Not logged in')
+  }
 }