fix(nostr-client): reconnect indefinitely instead of giving up after 5 attempts

Previously the relay reconnect logic gave up after 5 attempts (~31s).
If the relay was down longer, the ATM permanently lost connectivity
and couldn't fetch available balance — causing all bills to be
rejected after the recent safety guard change.

Now reconnects indefinitely with exponential backoff capped at 60s.
Attempts reset on successful connection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/nostr-client/src/client.ts

@@ -54,7 +54,7 @@ export class NostrClient {
     this.config = {
       connectionTimeout: 10000,
       autoReconnect: true,
-      maxReconnectAttempts: 5,
+      maxReconnectAttempts: Infinity,
       ...config,
     }
 
@@ -183,11 +183,16 @@ export class NostrClient {
     if (!connection) return
 
     if (connection.reconnectAttempts >= this.config.maxReconnectAttempts) {
+      console.warn(`[Nostr] Relay ${url}: max reconnect attempts reached`)
       return
     }
 
     connection.reconnectAttempts++
-    const delay = Math.min(1000 * Math.pow(2, connection.reconnectAttempts), 30000)
+    // Exponential backoff: 2s, 4s, 8s, 16s, 32s, then cap at 60s
+    const delay = Math.min(1000 * Math.pow(2, connection.reconnectAttempts), 60000)
+    console.log(
+      `[Nostr] Relay ${url}: reconnecting in ${delay / 1000}s (attempt ${connection.reconnectAttempts})`
+    )
 
     setTimeout(() => {
       this.connectToRelay(url)