Add app source and tests

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

lib/Peach/see/logs/ConnectLogs.dart

@@ -0,0 +1,16 @@
+abstract class ConnectLogs {
+  /// A fetch finished (the lines themselves arrive on the log stream).
+  void onLogsFetched();
+
+  /// The unit's current systemd status, e.g. `active (running)` or `no-unit`.
+  void onStatusLoaded(String status);
+
+  /// A start / stop / restart finished, with the message to surface.
+  void onControlFinished(String message);
+
+  /// Live tail started or stopped.
+  void onFollowChanged(bool following);
+
+  /// The filtered log text was written to [path], or cancelled when null.
+  void onLogsSaved(String? path);
+}