fix: Configure WalletConnect to use Grimoire's relay pool

Fixes missing subscription method error by wiring WalletConnect to use
Grimoire's singleton RelayPool for Nostr communication.

WalletConnect requires relay subscription and publish methods to
communicate with NWC wallet services. By setting the static pool property,
all WalletConnect instances automatically use Grimoire's existing relay
infrastructure for managing connections.

This enables:
- Wallet service discovery (waitForService)
- NIP-47 request/response communication (kinds 23194/23195)
- Balance queries, invoice generation, payment operations
- Proper relay connection management via the existing pool

src/services/wallet.ts

@@ -1,5 +1,9 @@
 import { WalletConnect } from "applesauce-wallet-connect";
 import { BehaviorSubject } from "rxjs";
+import pool from "./relay-pool";
+
+// Configure WalletConnect to use Grimoire's relay pool
+WalletConnect.pool = pool;
 
 export type WalletConnectionInfo = {
   id: string; // Unique identifier