fix(jellyfin): ensure autostart and modernize config

Forces autostart via Hyprland exec-once. Adds uosc, thumbfast, and better MPV defaults.

apps/jellyfin-mpv-shim/default.nix

@@ -60,7 +60,9 @@
     recursive = true;
   };
 
-  wayland.windowManager.hyprland.settings.windowrulev2 = [
+  wayland.windowManager.hyprland.settings = {
+    exec-once = [ "systemctl --user start jellyfin-mpv-shim" ];
+    windowrulev2 = [
       # --- JELLYFIN MPV SHIM ---
       "float, class:^(jellyfin-mpv-shim)$"
       "center, class:^(jellyfin-mpv-shim)$"
@@ -69,4 +71,5 @@
       "idleinhibit focus, class:^(jellyfin-mpv-shim)$"
       "noblur, class:^(jellyfin-mpv-shim)$"
     ];
+  };
 }