fix(shorebird_cli): ensure flutter artifacts are installed in shorebird preview (#1812)

packages/shorebird_cli/lib/src/commands/preview_command.dart

@@ -304,6 +304,8 @@ class PreviewCommand extends ShorebirdCommand {
     required DeploymentTrack track,
     String? deviceId,
   }) async {
+    await iosDeploy.installIfNeeded();
+
     const platform = ReleasePlatform.ios;
     final runnerDirectory = Directory(
       getArtifactPath(

packages/shorebird_cli/test/src/commands/preview_command_test.dart

@@ -976,6 +976,7 @@ channel: ${track.channel}
             device: any(named: 'device'),
           ),
         ).thenAnswer((_) async => ExitCode.success.code);
+        when(() => iosDeploy.installIfNeeded()).thenAnswer((_) async {});
         when(
           () => iosDeploy.installAndLaunchApp(
             bundlePath: any(named: 'bundlePath'),
@@ -1002,6 +1003,11 @@ channel: ${track.channel}
             ..createSync(recursive: true)
             ..writeAsStringSync('app_id: $appId', flush: true);
 
+      test('ensures ios-deploy is installed', () async {
+        await runWithOverrides(command.run);
+        verify(() => iosDeploy.installIfNeeded()).called(1);
+      });
+
       test('exits with code 70 when querying for release artifact fails',
           () async {
         final exception = Exception('oops');