Add app source and tests

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

lib/Peach/see/server/setup/ConnectServerSetup.dart

@@ -0,0 +1,12 @@
+import '../../../comms/Comms.dart' show DeployResult;
+
+abstract class ConnectServerSetup {
+  /// The server answered: its package manager and what's already installed.
+  void onServerProbed(String packageManager, Map<String, String> versions);
+
+  /// The server couldn't be reached or probed.
+  void onProbeFailed(String message);
+
+  /// The install finished; [versions] carries the re-probed tools.
+  void onInstallFinished(DeployResult result, Map<String, String> versions);
+}