fix(desktop): skip idle Host restart prompt

apps/desktop/src/main/__tests__/runtime-host-desktop-manager.test.ts

@@ -603,7 +603,7 @@ test('stops reconnecting when the replacement Host is incompatible', async () =>
   await owner.close();
 });
 
-test('restarts a generation-aware Host through its exact takeover handshake', async () => {
+test('restarts an idle generation-aware Host without prompting', async () => {
   const replacement = candidateHarness();
   const starts: DesktopRuntimeHostCandidateStartInput[] = [];
   const conflict = upgradeRequired(true);
@@ -613,7 +613,7 @@ test('restarts a generation-aware Host through its exact takeover handshake', as
       return starts.length === 1 ? conflict : ready(replacement.candidate);
     },
     upgradePrompts: {
-      restartable: async () => 'restart',
+      restartable: async () => assert.fail('idle Host must not prompt before restart'),
       waitOnly: async () => assert.fail('restartable conflict used wait-only prompt'),
     },
   });
@@ -623,6 +623,46 @@ test('restarts a generation-aware Host through its exact takeover handshake', as
   await owner.close();
 });
 
+test('prompts before restarting a generation-aware Host with active work', async () => {
+  const replacement = candidateHarness();
+  const conflict = upgradeRequired(true, 1);
+  let prompts = 0;
+  const owner = await startRuntimeHostDesktopManager({} as DesktopRuntimeHostCandidateStartInput, {
+    startCandidate: async (input) =>
+      input.takeoverHostEpoch ? ready(replacement.candidate) : conflict,
+    upgradePrompts: {
+      restartable: async () => {
+        prompts += 1;
+        return 'restart';
+      },
+      waitOnly: async () => assert.fail('restartable conflict used wait-only prompt'),
+    },
+  });
+
+  assert.equal(prompts, 1);
+  await owner.close();
+});
+
+test('prompts before restarting a generation-aware Host with a residency', async () => {
+  const replacement = candidateHarness();
+  const conflict = upgradeRequired(true, 0, [{ label: 'goal', count: 1 }]);
+  let prompts = 0;
+  const owner = await startRuntimeHostDesktopManager({} as DesktopRuntimeHostCandidateStartInput, {
+    startCandidate: async (input) =>
+      input.takeoverHostEpoch ? ready(replacement.candidate) : conflict,
+    upgradePrompts: {
+      restartable: async () => {
+        prompts += 1;
+        return 'restart';
+      },
+      waitOnly: async () => assert.fail('restartable conflict used wait-only prompt'),
+    },
+  });
+
+  assert.equal(prompts, 1);
+  await owner.close();
+});
+
 test('waits passively for a Host that cannot be taken over', async () => {
   const conflict = upgradeRequired(false);
   let starts = 0;
@@ -699,6 +739,8 @@ function incompatibleHost(
 
 function upgradeRequired(
   restartable: boolean,
+  activeOperations = 0,
+  residencies: readonly { readonly label: string; readonly count: number }[] = [],
 ): Extract<DesktopRuntimeHostCandidateStartResult, { kind: 'upgrade_required' }> {
   const registration = hostRegistration(
     restartable ? { lifecycleMode: 'ephemeral' } : {},
@@ -723,9 +765,9 @@ function upgradeRequired(
       replacement: 'blocked_by_residency',
       activity: {
         connections: 0,
-        activeOperations: 0,
+        activeOperations,
         processUptimeSeconds: 60,
-        residencies: [],
+        residencies,
       },
     },
   };

apps/desktop/src/main/runtime-host-desktop-manager.ts

@@ -582,7 +582,11 @@ class RuntimeHostDesktopManagerImpl implements RuntimeHostDesktopManager {
         return result.candidate;
       }
       if (result.kind === 'upgrade_required' && result.restartable) {
-        const decision = await this.#resolveRestartable(result);
+        const activity = result.handshake?.activity;
+        const decision =
+          activity && activity.activeOperations === 0 && activity.residencies.length === 0
+            ? 'restart'
+            : await this.#resolveRestartable(result);
         if (decision === 'cancel') {
           throw new RuntimeHostUpgradeCancelledError();
         }