feat(mobile): persist last Run-on destination

apps/mobile/src/components/agents/new-session-screen-body.tsx

@@ -39,6 +39,7 @@ import { useInstanceModelCatalog } from '@/lib/hooks/use-instance-model-catalog'
 import { useLaunchFolder } from '@/lib/hooks/use-launch-folder';
 import { useModelPreferences } from '@/lib/hooks/use-model-preferences';
 import { usePersistedAgentModel } from '@/lib/hooks/use-persisted-agent-model';
+import { usePersistedRunOnDestination } from '@/lib/hooks/use-persisted-run-on-destination';
 import { createRemoteModelOverride } from '@/lib/hooks/use-session-model-options';
 import {
   resolveContinueStartDisabled,
@@ -54,6 +55,7 @@ import {
 import { useDraftFlushOnBackground } from '@/lib/persist/use-draft-flush';
 import { useFencedDraftLoad, useRemoteSpawnDraftCleanup } from '@/lib/persist/use-draft-load';
 import { type InstancePickerInstance, type ModelPickerSelection } from '@/lib/picker-bridge';
+import { resolvePersistedRunOn } from '@/lib/run-on-destination';
 import { shouldShowRunOnSelector } from '@/lib/should-show-run-on-selector';
 import { peekSharePayload } from '@/lib/share-payload';
 import { useNewSessionShareRemote } from '@/lib/use-new-session-share-remote';
@@ -115,6 +117,8 @@ export function NewSessionScreenBody() {
   // without navigating (failure), so an abandon after a failed spawn still
   // confirms.
   const skipDiscardGuardRef = useRef(false);
+  const runOnRestoredRef = useRef(false);
+  const runOnUserPickedRef = useRef(false);
 
   const showRunOnSelector = shouldShowRunOnSelector(organizationId);
 
@@ -186,6 +190,11 @@ export function NewSessionScreenBody() {
   );
   const { setLastSelected: persistServerLastSelected } = useModelPreferences(organizationId);
   const { saveModel } = usePersistedAgentModel();
+  const {
+    storedConnectionId,
+    hasLoaded: hasLoadedRunOn,
+    saveRunOn,
+  } = usePersistedRunOnDestination();
   const attachments = useAgentAttachmentUpload({ organizationId });
 
   // Custom modes and the pinned model come from the effective default profile.
@@ -261,6 +270,17 @@ export function NewSessionScreenBody() {
     [instancesData]
   );
 
+  useEffect(() => {
+    if (runOnRestoredRef.current || runOnUserPickedRef.current) {
+      return;
+    }
+    if (!hasLoadedRunOn || instancesData === undefined) {
+      return;
+    }
+    runOnRestoredRef.current = true;
+    setRunOnInstance(resolvePersistedRunOn(storedConnectionId, instanceList));
+  }, [hasLoadedRunOn, instanceList, instancesData, storedConnectionId]);
+
   // A successful session creation owns clearing the new-session draft; a
   // failure must preserve it for the retry. The success path navigates via
   // `replace`, so arm the discard-confirm bypass here — `onCreated` runs
@@ -410,11 +430,13 @@ export function NewSessionScreenBody() {
 
   const handleRunOnChange = useCallback(
     (next: InstancePickerInstance | null) => {
+      runOnUserPickedRef.current = true;
+      saveRunOn(next?.connectionId ?? null);
       setRemoteOverride(null);
       setCloneImportFailureKey(null);
       handleRunOnInstanceChange(next);
     },
-    [handleRunOnInstanceChange]
+    [handleRunOnInstanceChange, saveRunOn]
   );
 
   function handlePromptChange(text: string) {

apps/mobile/src/lib/auth/auth-context.test.tsx

@@ -216,6 +216,10 @@ vi.mock('@/lib/hooks/use-persisted-agent-model', () => ({
   clearAgentModelPreference: vi.fn(),
 }));
 
+vi.mock('@/lib/hooks/use-persisted-run-on-destination', () => ({
+  clearRunOnDestinationPreference: vi.fn(),
+}));
+
 const { clearKeepScreenOnPreference, clearReasoningPreference, clearPrReviewFooterPreference } =
   vi.hoisted(() => ({
     clearKeepScreenOnPreference: vi.fn(),
@@ -616,6 +620,9 @@ describe('sign-out teardown ordering', () => {
     expect(clearKeepScreenOnPreference).toHaveBeenCalled();
     expect(clearReasoningPreference).toHaveBeenCalled();
     expect(clearPrReviewFooterPreference).toHaveBeenCalled();
+    const { clearRunOnDestinationPreference } =
+      await import('@/lib/hooks/use-persisted-run-on-destination');
+    expect(clearRunOnDestinationPreference).toHaveBeenCalled();
   });
 
   it('closes the ownership gate before any await and blocks a late persist', async () => {

apps/mobile/src/lib/auth/auth-context.tsx

@@ -45,6 +45,7 @@ import {
 import { readStoredValueWithRetry } from '@/lib/auth/secure-store-read';
 import { chainSave } from '@/lib/hooks/save-chain';
 import { clearAgentModelPreference } from '@/lib/hooks/use-persisted-agent-model';
+import { clearRunOnDestinationPreference } from '@/lib/hooks/use-persisted-run-on-destination';
 import { clearKeepScreenOnPreference } from '@/lib/hooks/use-keep-screen-on-preference';
 import { clearLiveActivityPreference } from '@/lib/hooks/use-live-activity-preference';
 import { clearPrReviewFooterPreference } from '@/lib/hooks/use-pr-review-footer-preference';
@@ -476,6 +477,7 @@ export function AuthProvider({ children }: { readonly children: ReactNode }) {
           // Synchronous preference clears (best-effort) so nothing leaks to
           // the next signed-in account.
           clearAgentModelPreference();
+          clearRunOnDestinationPreference();
           clearReasoningPreference();
           clearKeepScreenOnPreference();
           clearLiveActivityPreference();

apps/mobile/src/lib/auth/credentials.test.ts

@@ -58,6 +58,9 @@ vi.mock('@/lib/query-client', () => ({
 }));
 vi.mock('@/lib/auth/trpc-unauthorized', () => ({ setTrpcUnauthorizedHandler: vi.fn() }));
 vi.mock('@/lib/hooks/use-persisted-agent-model', () => ({ clearAgentModelPreference: vi.fn() }));
+vi.mock('@/lib/hooks/use-persisted-run-on-destination', () => ({
+  clearRunOnDestinationPreference: vi.fn(),
+}));
 vi.mock('@/lib/hooks/use-keep-screen-on-preference', () => ({
   clearKeepScreenOnPreference: vi.fn(),
 }));

apps/mobile/src/lib/hooks/use-persisted-run-on-destination.ts

@@ -0,0 +1,26 @@
+import { useSyncExternalStore } from 'react';
+
+import { createSecureStorePreference } from '@/lib/hooks/secure-store-preference';
+import { parseStoredRunOnDestination } from '@/lib/run-on-destination';
+import { LAST_RUN_ON_DESTINATION_KEY } from '@/lib/storage-keys';
+
+const store = createSecureStorePreference<string | null>({
+  key: LAST_RUN_ON_DESTINATION_KEY,
+  defaultValue: null,
+  parse: parseStoredRunOnDestination,
+  serialize: value => value ?? '',
+});
+
+export function clearRunOnDestinationPreference() {
+  store.clear();
+}
+
+function saveRunOn(connectionId: string | null) {
+  store.set(connectionId);
+}
+
+export function usePersistedRunOnDestination() {
+  const storedConnectionId = useSyncExternalStore(store.subscribe, store.get);
+  const hasLoaded = useSyncExternalStore(store.subscribe, store.getHasLoaded);
+  return { storedConnectionId, hasLoaded, saveRunOn };
+}

apps/mobile/src/lib/run-on-destination.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, it } from 'vitest';
+
+import { parseStoredRunOnDestination, resolvePersistedRunOn } from './run-on-destination';
+
+const CLI = { connectionId: 'cli-1', name: 'MacBook' };
+const REMOTE = { connectionId: 'remote-1', name: 'VM' };
+
+describe('parseStoredRunOnDestination', () => {
+  it('treats missing or empty storage as Cloud Agent', () => {
+    expect(parseStoredRunOnDestination(null)).toBeNull();
+    expect(parseStoredRunOnDestination('')).toBeNull();
+  });
+
+  it('returns a stored connection id', () => {
+    expect(parseStoredRunOnDestination('cli-1')).toBe('cli-1');
+  });
+});
+
+describe('resolvePersistedRunOn', () => {
+  it('defaults to Cloud Agent when nothing is stored', () => {
+    expect(resolvePersistedRunOn(null, [CLI])).toBeNull();
+  });
+
+  it('returns the live row when the stored id is in the list', () => {
+    expect(resolvePersistedRunOn('cli-1', [REMOTE, CLI])).toBe(CLI);
+  });
+
+  it('falls back to Cloud Agent when the stored id is gone', () => {
+    expect(resolvePersistedRunOn('cli-1', [REMOTE])).toBeNull();
+    expect(resolvePersistedRunOn('cli-1', [])).toBeNull();
+  });
+});

apps/mobile/src/lib/run-on-destination.ts

@@ -0,0 +1,16 @@
+export function parseStoredRunOnDestination(raw: string | null): string | null {
+  if (!raw) {
+    return null;
+  }
+  return raw;
+}
+
+export function resolvePersistedRunOn<T extends { connectionId: string }>(
+  storedConnectionId: string | null,
+  instances: readonly T[]
+): T | null {
+  if (!storedConnectionId) {
+    return null;
+  }
+  return instances.find(instance => instance.connectionId === storedConnectionId) ?? null;
+}

apps/mobile/src/lib/storage-keys.ts

@@ -14,6 +14,8 @@ export const SESSION_FILTERS_KEY = 'agent-session-filters';
 export const LIVE_SESSION_FILTERS_KEY = 'live-session-filters';
 export const NOTIFICATION_PROMPT_SEEN_KEY = 'notification-prompt-seen';
 export const LAST_ACTIVE_INSTANCE_KEY = 'last-active-chat-instance';
+/** Last "Run on" destination on the new-agent screen. Empty means Cloud Agent. */
+export const LAST_RUN_ON_DESTINATION_KEY = 'last-run-on-destination';
 export const CONSENT_USER_KEY_PREFIX = 'consent-accepted-';
 export const AGENT_MODEL_PREFERENCE_KEY = 'agent-model-preference';
 export const REASONING_DEFAULT_EXPANDED_KEY = 'agent-reasoning-default-expanded';