Add app source and tests

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

lib/Peach/see/deploy/batch/ConnectBatchDeploy.dart

@@ -0,0 +1,13 @@
+/// Where one service has got to in the batch.
+enum BatchState { queued, building, deploying, done, failed, skipped }
+
+abstract class ConnectBatchDeploy {
+  /// The run started; every selected service is queued.
+  void onBatchStarted(List<String> serviceIds);
+
+  /// One service moved to a new state, optionally with a detail line.
+  void onServiceState(String serviceId, BatchState state, {String? detail});
+
+  /// Every service in the batch has been attempted.
+  void onBatchFinished();
+}