some fixes

cht/ui/keyboard.py

@@ -41,15 +41,18 @@ class KeyboardManager:
     def __init__(self):
         self._bindings: dict[int, Callable] = {}
         self._passthrough: Callable[[], bool] | None = None
+        self._passthrough_except: set[int] = set()
         self._window = None
 
     def bind(self, keyval: int, handler: Callable):
         """Register a handler for a key. Handler receives shift=bool."""
         self._bindings[keyval] = handler
 
-    def set_passthrough(self, check: Callable[[], bool]):
-        """When check() returns True, keys pass through to focused widget."""
+    def set_passthrough(self, check: Callable[[], bool], except_keys: set[int] | None = None):
+        """When check() returns True, keys pass through to focused widget.
+        Keys in except_keys are still handled even during passthrough."""
         self._passthrough = check
+        self._passthrough_except = except_keys or set()
 
     def attach(self, window):
         """Attach to a GTK4 window."""
@@ -76,7 +79,7 @@ class KeyboardManager:
             self._window.set_focus(None)
 
     def _on_key_pressed(self, controller, keyval, keycode, state):
-        if self._passthrough and self._passthrough():
+        if self._passthrough and self._passthrough() and keyval not in self._passthrough_except:
             return False
 
         handler = self._bindings.get(keyval)