Add app source and tests

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

lib/Peach/see/docker/run/ConnectDockerRun.dart

@@ -0,0 +1,5 @@
+abstract class ConnectDockerRun {
+  /// The run finished: [started] is whether the container came up, and
+  /// [output] is the container id on success or the failure text.
+  void onRunFinished(bool started, String output);
+}