refactor(theme): Introduce semantic theme layer and clean NERV cruft from gui_2.py

src/imgui_scopes.py

@@ -86,6 +86,21 @@ class _ScopePopup:
    imgui.end_popup()
   return False
 
+def popup_modal(name: str, visible: bool = True, flags: int = 0): return _ScopePopupModal(name, visible, flags)
+class _ScopePopupModal:
+ def __init__(self, name: str, visible: bool, flags: int):
+  self._name = name
+  self._visible = visible
+  self._flags = flags
+  self._active = False
+ def __enter__(self):
+  self._active, self._visible = imgui.begin_popup_modal(self._name, self._visible, self._flags)
+  return self._active, self._visible
+ def __exit__(self, *args):
+  if self._active:
+   imgui.end_popup()
+  return False
+
 def tooltip(): return _ScopeTooltip()
 class _ScopeTooltip:
  def __enter__(self):