hypr: move session daemons from exec-once to systemd user services

Replace the hl.exec_cmd autostart block with declarative home-manager
services so the desktop shell has proper ordering and lifecycle:

- services.hyprpaper (with settings) for hyprpaper
- services.cliphist for the text/image clipboard watchers
- services.hyprpolkitagent for the polkit agent
- programs.quickshell.systemd for the quickshell shell
- a hand-written systemd.user.services.mako (home-manager has no unit)

All are tied to config.wayland.systemd.target (graphical-session.target),
which start-hyprland already activates. No UWSM required.

home/hypr/hyprland.nix

@@ -1,5 +1,4 @@
 {
-  pkgs,
   lib,
   config,
   ...
@@ -282,24 +281,12 @@ in
         ];
 
         # -----------------------------------------------------------------------
-        # 6. Autostart Daemons & Apps (hl.on)
+        # 6. Autostart Daemons & Apps
         # -----------------------------------------------------------------------
-        on = [
-          {
-            _args = [
-              "hyprland.start"
-              (mkLua ''
-                function()
-                              hl.exec_cmd("qs")
-                              hl.exec_cmd("hyprpaper")
-                              hl.exec_cmd("mako")
-                              hl.exec_cmd("wl-paste --type text --watch cliphist store")
-                              hl.exec_cmd("wl-paste --type image --watch cliphist store")
-                              hl.exec_cmd("${pkgs.hyprpolkitagent}/libexec/hyprpolkitagent")
-                            end'')
-            ];
-          }
-        ];
+        # Desktop daemons (quickshell, hyprpaper, mako, cliphist and the
+        # polkit agent) are declared as systemd user services in
+        # home/hypr/services.nix and home/hypr/quickshell.nix, tied to the
+        # Wayland session target instead of exec-once.
 
         # -----------------------------------------------------------------------
         # 7. Keybindings (hl.bind)