refactor(gui): Refactor main panels to use imscope and fix regression in test suite

tests/test_gui_phase4.py

@@ -70,11 +70,19 @@ def test_delete_ticket_logic(mock_app: App):
 def test_track_discussion_toggle(mock_app: App):
  with (
   patch('src.gui_2.imgui') as mock_imgui, 
+  patch('src.gui_2.imscope') as mock_imscope,
   patch('src.gui_2.project_manager.load_track_history', return_value=["@2026-03-01 12:00:00\n[User]\nTrack Hello"]) as mock_load, 
   patch('src.gui_2.project_manager.str_to_entry', side_effect=lambda s, roles: {"ts": "12:00", "role": "User", "content": s.split("\n")[-1]}),
   patch.object(mock_app.controller, '_flush_disc_entries_to_project') as mock_flush, 
   patch.object(mock_app.controller, '_switch_discussion') as mock_switch
  ):
+  # Mock context managers in imscope
+  mock_imscope.id.return_value.__enter__.return_value = None
+  mock_imscope.child.return_value.__enter__.return_value = True
+  mock_imscope.tab_item.return_value.__enter__.return_value = (True, True)
+  mock_imscope.style_color.return_value.__enter__.return_value = None
+  mock_imscope.style_var.return_value.__enter__.return_value = None
+  
   # Track calls to ensure we only return 'changed=True' once to avoid loops
   calls = {"Track Discussion": 0}
   def checkbox_side_effect(label, value):