refactor(gui2): Restructure layout into discrete Hubs

Automates the refactoring of the monolithic _gui_func in gui_2.py into separate rendering methods, nested within 'Context Hub', 'AI Settings Hub', 'Discussion Hub', and 'Operations Hub', utilizing tab bars. Adds tests to ensure the new default windows correctly represent this Hub structure.

tests/test_gui2_layout.py

@@ -0,0 +1,46 @@
+import pytest
+from unittest.mock import patch
+from gui_2 import App
+
+@pytest.fixture
+def app_instance():
+    with (
+         patch('gui_2.load_config', return_value={'gui': {'show_windows': {}}}),
+         patch('gui_2.save_config'),
+         patch('gui_2.project_manager'),
+         patch('gui_2.session_logger'),
+         patch('gui_2.immapp.run'),
+         patch.object(App, '_load_active_project'),
+         patch.object(App, '_fetch_models'),
+         patch.object(App, '_load_fonts'),
+         patch.object(App, '_post_init')
+    ):
+        yield App()
+
+def test_gui2_hubs_exist_in_show_windows(app_instance):
+    """
+    Verifies that the new consolidated Hub windows are defined in the App's show_windows.
+    This ensures they will be available in the 'Windows' menu.
+    """
+    expected_hubs = [
+        "Context Hub",
+        "AI Settings Hub",
+        "Discussion Hub",
+        "Operations Hub",
+    ]
+    
+    for hub in expected_hubs:
+        assert hub in app_instance.show_windows, f"Expected hub window '{hub}' not found in show_windows"
+
+def test_gui2_old_windows_removed_from_show_windows(app_instance):
+    """
+    Verifies that the old fragmented windows are removed from show_windows.
+    """
+    old_windows = [
+        "Projects", "Files", "Screenshots",
+        "Provider", "System Prompts",
+        "Message", "Response", "Tool Calls", "Comms History"
+    ]
+    
+    for old_win in old_windows:
+        assert old_win not in app_instance.show_windows, f"Old window '{old_win}' should have been removed from show_windows"