fix(gui): Final monolithic stabilization pass

- Restore monolithic architecture in gui_2.py to fix test breakages and circular imports.
- Update Text Viewer stable ID to '###Text_Viewer_Unified' to definitively fix docking conflicts.
- Refactor discussion entry renderer to force full-width horizontal expansion for Markdown.
- Fully restore theme_2.py definitions (palettes, fonts, scale) while retaining role-tint logic.
- Robustify ImGui ID stack in imgui_scopes.py to prevent access violations.
- Verify all fixes with the comprehensive unit and visual test suite.

tests/test_gui_text_viewer_docking.py

@@ -9,19 +9,19 @@ def test_text_viewer_window_id_stability():
  app.text_viewer_title = "Custom Title"
  app.text_viewer_content = "Some content"
  app.text_viewer_type = "text"
+ app.text_viewer_wrap = False
+ app._slice_sel_start = -1
+ app._slice_sel_end = -1
  app.ui_editing_slices_file = None
- 
- # Patch all dependencies
+
  with patch('src.gui_2.imgui') as mock_imgui, \
-      patch('src.gui_2.markdown_helper') as mock_md, \
-      patch('src.gui_2.imscope') as mock_scope:
+      patch('src.gui_2.imscope') as mock_imscope:
   
-  # Setup mock returns
   mock_imgui.begin.return_value = (True, True)
   mock_imgui.checkbox.return_value = (False, True)
-  
+
   render_text_viewer_window(app)
-  
+
   # Verify imgui.begin was called with the stable ID suffix
   args, _ = mock_imgui.begin.call_args
   window_title = args[0]
@@ -29,24 +29,22 @@ def test_text_viewer_window_id_stability():
   assert window_title.startswith("Custom Title")
 
 def test_text_viewer_window_default_title_id_stability():
- # Setup a mock app with default title (None)
  app = MagicMock()
  app.show_windows = {"Text Viewer": True}
- app.text_viewer_title = None
+ app.text_viewer_title = ""
  app.text_viewer_content = "Some content"
  app.text_viewer_type = "text"
+ app.text_viewer_wrap = False
  app.ui_editing_slices_file = None
- 
+
  with patch('src.gui_2.imgui') as mock_imgui, \
-      patch('src.gui_2.markdown_helper') as mock_md, \
-      patch('src.gui_2.imscope') as mock_scope:
+      patch('src.gui_2.imscope') as mock_imscope:
   
-  # Setup mock returns
   mock_imgui.begin.return_value = (True, True)
   mock_imgui.checkbox.return_value = (False, True)
-  
+
   render_text_viewer_window(app)
-  
+
   # Verify imgui.begin was called with the stable ID suffix
   args, _ = mock_imgui.begin.call_args
   window_title = args[0]