chore(bunker): warn if remote pubkey equals user pubkey (invalid state)

- Add sanity check and toast guidance to reconnect via Amber
- Helps catch misconfigured bunker URIs that would never respond to requests

src/App.tsx

@@ -259,6 +259,11 @@ function App() {
               
               if (account && account.type === 'nostr-connect') {
                 const nostrConnectAccount = account as Accounts.NostrConnectAccount<unknown>
+                // Sanity check: remote (bunker) pubkey must not equal our pubkey
+                if (nostrConnectAccount.signer.remote === nostrConnectAccount.pubkey) {
+                  console.warn('[bunker] ❌ Invalid bunker state: remote pubkey equals user pubkey. Please reconnect using a fresh bunker URI from Amber.')
+                  try { showToast?.('Reconnect bunker from Amber: invalid remote pubkey detected') } catch {}
+                }
                 
                 // Skip if we've already reconnected this account
                 if (reconnectedAccounts.has(account.id)) {