fix: consume owner monitor transition failures

src/stores/wallet.lifecycle.invalidation.cases.ts

@@ -1,10 +1,11 @@
-import { MINT_KEY, OTHER_OWNER_ID, PASSWORD } from './wallet.lifecycle.testHarness';
+import { MINT_KEY, mocks, OTHER_OWNER_ID, PASSWORD } from './wallet.lifecycle.testHarness';
 import { describe, expect, it, vi } from 'vitest';
 
 import { savedKeyOwnerId } from '@/lnurlcash/keys';
 import { readNwcEnabled, writeNwcConnections, writeNwcEnabled } from '@/lnurlcash/nwc';
 import type { NwcConnectionRecord } from '@/lnurlcash/nwc';
 import { addTrustedMint, readTrustedMints } from '@/lnurlcash/trustedMints';
+import { useNwcStore } from './nwc';
 import { useWalletStore } from './wallet';
 
 describe('cross-tab owner invalidation', () => {
@@ -41,6 +42,36 @@ describe('cross-tab owner invalidation', () => {
     expect(readNwcEnabled(OTHER_OWNER_ID)).toBe(false);
   });
 
+  it('surfaces a failed stale-tab drain without an unhandled rejection', async () => {
+    // Given an unlocked old-owner tab whose live NWC service rejects shutdown
+    const events = new EventTarget();
+    vi.stubGlobal('window', events);
+    const wallet = useWalletStore();
+    const nwc = useNwcStore();
+    await wallet.create(PASSWORD);
+    const serviceStop = vi.fn().mockRejectedValue(new Error('stale drain failed'));
+    mocks.startService.mockResolvedValue({ connections: [], stop: serviceStop });
+    await nwc.setEnabled(true);
+
+    // When another tab replaces the saved wallet owner
+    localStorage.setItem(
+      'sattle_linking_key',
+      JSON.stringify({ enc: false, value: '09'.repeat(32), ownerId: OTHER_OWNER_ID, version: 1 }),
+    );
+    events.dispatchEvent(
+      Object.defineProperties(new Event('storage'), {
+        key: { value: 'sattle_linking_key' },
+      }),
+    );
+    await vi.waitFor(() => expect(wallet.state).toBe('locked'));
+
+    // Then the stale runtime is cleared and the queue surfaces the drain failure
+    expect(wallet.lifecycleError).toMatch(/stale drain failed/i);
+    expect(() => wallet.requireLinkingKey()).toThrow('Wallet is locked.');
+    expect(nwc.running).toBe(false);
+    expect(serviceStop).toHaveBeenCalledTimes(1);
+  });
+
   it('rejects old-owner trust and NWC writes during the markerless forget gap', async () => {
     // Given wallet A was active and an old tab retained only its owner identifier
     const wallet = useWalletStore();

src/stores/walletOwnerMonitor.test.ts

@@ -0,0 +1,47 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+import { linkingPubKeyHex } from '@/lnurlcash/keys';
+import { stubLocalStorage } from '@/lnurlcash/test-utils';
+import { startWalletOwnerMonitor } from './walletOwnerMonitor';
+
+const OWNER_ID = linkingPubKeyHex(new Uint8Array(32).fill(7));
+const OTHER_OWNER_ID = linkingPubKeyHex(new Uint8Array(32).fill(9));
+
+describe('wallet owner monitor', () => {
+  beforeEach(() => {
+    vi.unstubAllGlobals();
+    stubLocalStorage();
+  });
+
+  it('consumes a background transition rejection after an owner replacement', () => {
+    // Given an unlocked stale owner and a transition promise observed by the queue
+    const events = new EventTarget();
+    vi.stubGlobal('window', events);
+    localStorage.setItem(
+      'sattle_linking_key',
+      JSON.stringify({
+        enc: false,
+        value: '09'.repeat(32),
+        ownerId: OTHER_OWNER_ID,
+        version: 1,
+      }),
+    );
+    const transition = Promise.resolve();
+    const catchRejection = vi.spyOn(transition, 'catch');
+    startWalletOwnerMonitor({
+      snapshot: () => ({ token: 1, state: 'unlocked', ownerId: OWNER_ID }),
+      deactivate: vi.fn().mockResolvedValue(undefined),
+      runTransition: vi.fn().mockReturnValue(transition),
+    });
+
+    // When the browser reports that the saved owner changed
+    events.dispatchEvent(
+      Object.defineProperties(new Event('storage'), {
+        key: { value: 'sattle_linking_key' },
+      }),
+    );
+
+    // Then the fire-and-forget transition has a rejection consumer
+    expect(catchRejection).toHaveBeenCalledOnce();
+  });
+});

src/stores/walletOwnerMonitor.ts

@@ -24,7 +24,8 @@ export const startWalletOwnerMonitor = (monitor: WalletOwnerMonitor): (() => voi
     ) {
       return;
     }
-    void monitor.runTransition(async () => {
+    void monitor
+      .runTransition(async () => {
         const current = monitor.snapshot();
         if (
           current.token !== expected.token ||
@@ -35,5 +36,6 @@ export const startWalletOwnerMonitor = (monitor: WalletOwnerMonitor): (() => voi
           return;
         }
         await monitor.deactivate();
-    });
+      })
+      .catch(() => undefined);
   });