fix(setup): Tolerate device fallback discovery failures

Return an empty device list when both devicectl and xctrace discovery fail so setup can continue with no default device instead of aborting. Add regression coverage for the double-failure discovery path.

Author: cameroncooke

src/cli/commands/__tests__/setup.test.ts

@@ -679,6 +679,68 @@ sessionDefaults:
     expect(parsed.sessionDefaults?.deviceId).toBeUndefined();
   });
 
+  it('continues setup with no default device when both discovery commands fail', async () => {
+    const { fs, getStoredConfig } = createSetupFs();
+
+    const executor: CommandExecutor = async (command) => {
+      if (command[0] === 'xcrun' && command[1] === 'devicectl') {
+        throw new Error('devicectl unavailable');
+      }
+
+      if (command[0] === 'xcrun' && command[1] === 'xctrace') {
+        return createMockCommandResponse({ success: false, output: '', error: 'xctrace failed' });
+      }
+
+      if (command.includes('--json')) {
+        return createMockCommandResponse({
+          success: true,
+          output: JSON.stringify({
+            devices: {
+              'iOS 17.0': [
+                {
+                  name: 'iPhone 15',
+                  udid: 'SIM-1',
+                  state: 'Shutdown',
+                  isAvailable: true,
+                },
+              ],
+            },
+          }),
+        });
+      }
+
+      return createMockCommandResponse({
+        success: true,
+        output: `Information about workspace "App":\n    Schemes:\n        App`,
+      });
+    };
+
+    const prompter: Prompter = {
+      selectOne: async <T>(opts: { options: Array<{ value: T }> }) => opts.options[0].value,
+      selectMany: async <T>(opts: { options: Array<{ value: T }> }) => {
+        const loggingOption = opts.options.find((option) => option.value === ('logging' as T));
+        return loggingOption ? [loggingOption.value] : opts.options.map((option) => option.value);
+      },
+      confirm: async (opts: { defaultValue: boolean }) => opts.defaultValue,
+    };
+
+    await runSetupWizard({
+      cwd,
+      fs,
+      executor,
+      prompter,
+      quietOutput: true,
+    });
+
+    const parsed = parseYaml(getStoredConfig()) as {
+      sessionDefaults?: Record<string, unknown>;
+    };
+
+    expect(parsed.sessionDefaults?.deviceId).toBeUndefined();
+    expect(parsed.sessionDefaults?.simulatorId).toBeUndefined();
+    expect(parsed.sessionDefaults?.simulatorName).toBeUndefined();
+  });
+
   it('continues setup with no default simulator when no simulators are available', async () => {
     const { fs, getStoredConfig } = createSetupFs();
 

src/cli/commands/setup.ts

@@ -574,7 +574,7 @@ async function listAvailableDevices(
   );
 
   if (!fallbackResult.success) {
-    throw new Error(`Failed to list devices: ${fallbackResult.error}`);
+    return [];
   }
 
   return parseXctraceDevices(fallbackResult.output);