v0.5.0: CAT token service improvements

- Improved Cashu Access Token handling
- Version bump to v0.5.0

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "smesh",
-  "version": "0.4.1",
+  "version": "0.5.0",
   "description": "A user-friendly Nostr client for exploring relay feeds",
   "private": true,
   "type": "module",

src/services/cashu-token.service.ts

@@ -319,10 +319,12 @@ class CashuTokenService {
     }
 
     const result = await response.json()
+    console.log('[CAT] Mint response:', JSON.stringify(result))
 
     // Unblind the signature
+    // Field name is "pubkey" per NIP-XX Cashu Access Tokens spec
     const C_ = utils.hexToBytes(result.blinded_signature)
-    const K = utils.hexToBytes(result.mint_pubkey)
+    const K = utils.hexToBytes(result.pubkey)
     const signature = unblind(C_, blindResult.r, K)
 
     const token: TCashuToken = {