fix: clean up GTK/WebKit integration and event handling

- fix split pane expansion/orientation setup logic
- remove deferred pane positioning on show events
- load VTE with interactive bash rcfile
- migrate WebKit2 bindings from 4.0 to 4.1
- add icons path accessor to PathManager
- normalize startup IPC file event payloads with FILE| prefix
- alias App_Event_Types and update plugin event references
- guard widget registry against unnamed builder objects
- fix application_dirs home path lookup
- remove unused GLib import from completion controller
- reorder setproctitle import in __main__

src/core/widgets/vte_widget.py

@@ -88,7 +88,7 @@ class VteWidget(Vte.Terminal):
         self.spawn_async(
             Vte.PtyFlags.DEFAULT,
             settings_manager.path_manager.get_home_path(),
-            ["/bin/bash"],
+            ["/bin/bash", "--rcfile", f"{settings_manager.path_manager.get_home_path()}/.bashrc", "-i"],
             env,
             GLib.SpawnFlags.DEFAULT,
             None, None, -1, None, None,