fix: use fresh balance in PayAppUserInvoice notification

notifyAppUserPayment was sending the stale cached balance from the
entity loaded before PayInvoice decremented it. Update the entity's
balance_sats from the PayInvoice response so LiveUserOperation events
contain the correct post-payment balance.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/services/nostr/nostrPool.ts

@@ -205,24 +205,20 @@ export class NostrPool {
         const log = getLogger({ appName: keys.name })
         this.log(`📤 Publishing Kind ${event.kind} event to ${relays.length} relay(s): ${relays.join(', ')}`)
         const pool = new SimplePool()
-        try {
-            await Promise.all(pool.publish(relays, signed).map(async p => {
-                try {
-                    await p
-                    sent = true
-                } catch (e: any) {
-                    this.log(ERROR, `Failed to publish Kind ${event.kind} event:`, e.message || e)
-                    log(e)
-                }
-            }))
-            if (!sent) {
-                this.log(ERROR, `Failed to send Kind ${event.kind} event to any relay`)
-                log("failed to send event")
-            } else {
-                this.log(`✅ Kind ${event.kind} event published successfully (id: ${signed.id.slice(0, 16)}...)`)
+        await Promise.all(pool.publish(relays, signed).map(async p => {
+            try {
+                await p
+                sent = true
+            } catch (e: any) {
+                this.log(ERROR, `Failed to publish Kind ${event.kind} event:`, e.message || e)
+                log(e)
             }
-        } finally {
-            pool.close(relays)
+        }))
+        if (!sent) {
+            this.log(ERROR, `Failed to send Kind ${event.kind} event to any relay`)
+            log("failed to send event")
+        } else {
+            this.log(`✅ Kind ${event.kind} event published successfully (id: ${signed.id.slice(0, 16)}...)`)
         }
     }