settings.py: support ~ expansion for sound path

src/backend/backend.py

@@ -592,6 +592,7 @@ class Backend:
 
     async def sound_notify(self) -> None:
         path = self.settings.Notifications.default_sound
+        path = str(Path(path).expanduser())
 
         if path == "default.wav":
             path = "src/sounds/default.wav"

src/config/settings.py

@@ -58,7 +58,7 @@ class Notifications:
 
     # Default sound to play for notifications. Can be the filename
     # of a builtin sound (only "default.wav" currently exists), or the
-    # absolute path to a WAV file.
+    # absolute path to a WAV file (supports ~ user expansion).
     default_sound: str = "default.wav"
 
     # How long in seconds the window will flash in your dock or taskbar when