feat(wallet): Production-ready wallet with real blockchain integration

Wallet Features:
- Fix address encoding (48 byte → 32 byte) for chain queries
- Add gas fee preview before sending transactions
- Add address validation with error display
- Add real-time balance via chain subscription
- Add address book (save/load frequently used addresses)
- Add balance check before send (insufficient funds warning)
- Use transferKeepAlive to prevent account reaping

UI/UX:
- Browser title: "Pezkuwi Wallet" → "Pezkuwi"
- Update favicon from shared/images
- Standardize token logos (hez_token_512.png, pez_token_512.png)

Infrastructure:
- Fix zombienet endpoint: wss://beta-rpc.pezkuwichain.io:19944
- Disable indexer API (not production ready yet)
- Optimize logo images for mobile (5MB → 300KB)

mobile/app.json

@@ -1,7 +1,7 @@
 {
   "expo": {
-    "name": "Pezkuwi Wallet",
-    "slug": "pezkuwi-wallet",
+    "name": "Pezkuwi",
+    "slug": "pezkuwi",
     "version": "1.0.0",
     "orientation": "portrait",
     "icon": "./assets/icon.png",