feat(tier4): Complete GUI integration for patch modal

- Add patch modal state to AppController instead of App
- Add show_patch_modal/hide_patch_modal action handlers
- Fix push_event to work with flat payload format
- Add patch fields to _gettable_fields
- Both GUI integration tests passing

src/app_controller.py

@@ -137,6 +137,10 @@ class AppController:
   self.active_track: Optional[models.Track] = None
   self.active_tickets: List[Dict[str, Any]] = []
   self.mma_streams: Dict[str, str] = {}
+  self._pending_patch_text: Optional[str] = None
+  self._pending_patch_files: List[str] = []
+  self._show_patch_modal: bool = False
+  self._patch_error_message: Optional[str] = None
   self.mma_status: str = "idle"
   self._tool_log: List[Dict[str, Any]] = []
   self._comms_log: List[Dict[str, Any]] = []
@@ -294,7 +298,10 @@ class AppController:
     'tracks': 'tracks',
     'thinking_indicator': 'thinking_indicator',
     'operations_live_indicator': 'operations_live_indicator',
-    'prior_session_indicator': 'prior_session_indicator'
+    'prior_session_indicator': 'prior_session_indicator',
+    '_show_patch_modal': '_show_patch_modal',
+    '_pending_patch_text': '_pending_patch_text',
+    '_pending_patch_files': '_pending_patch_files'
    })
   self._init_actions()
 
@@ -518,21 +525,11 @@ class AppController:
       self._ask_request_id = None
       self._ask_tool_data = None
     elif action == "custom_callback":
-     sys.stderr.write(f"[DEBUG] Processing custom_callback task\n")
-     sys.stderr.flush()
      cb = task.get("callback")
      args = task.get("args", [])
      if callable(cb):
-      try: 
-       sys.stderr.write(f"[DEBUG] Calling callable callback\n")
-       sys.stderr.flush()
-       cb(*args)
-       sys.stderr.write(f"[DEBUG] Callback completed\n")
-       sys.stderr.flush()
-      except Exception as e: 
-       sys.stderr.write(f"[DEBUG] Error in direct custom callback: {e}\n")
-       sys.stderr.flush()
-       print(f"Error in direct custom callback: {e}")
+      try: cb(*args)
+      except Exception as e: print(f"Error in direct custom callback: {e}")
      elif cb in self._predefined_callbacks:
       self._predefined_callbacks[cb](*args)
     elif action == "mma_step_approval":
@@ -542,6 +539,14 @@ class AppController:
       task["dialog_container"][0] = dlg
     elif action == 'refresh_from_project':
      self._refresh_from_project()
+    elif action == "show_patch_modal":
+     self._pending_patch_text = task.get("patch_text", "")
+     self._pending_patch_files = task.get("file_paths", [])
+     self._show_patch_modal = True
+    elif action == "hide_patch_modal":
+     self._show_patch_modal = False
+     self._pending_patch_text = None
+     self._pending_patch_files = []
     elif action == "mma_spawn_approval":
      spawn_dlg = MMASpawnApprovalDialog(
       str(task.get("ticket_id") or ""),