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/services.nix

@@ -0,0 +1,37 @@
+{
+  config,
+  pkgs,
+  ...
+}:
+
+let
+  # The Wayland session target used by the home-manager Wayland modules
+  # (resolves to graphical-session.target). start-hyprland activates it.
+  sessionTarget = config.wayland.systemd.target;
+in
+{
+  # PolicyKit agent (replaces the old hl.exec_cmd autostart).
+  services.hyprpolkitagent.enable = true;
+
+  # Clipboard history. The module runs both the text and image watchers as
+  # systemd user services and adds the cliphist package.
+  services.cliphist.enable = true;
+
+  # mako has no systemd service in home-manager, so declare one here.
+  # Configuration lives next to the rest of the desktop theme in default.nix.
+  systemd.user.services.mako = {
+    Unit = {
+      Description = "mako notification daemon";
+      After = [ sessionTarget ];
+      PartOf = [ sessionTarget ];
+    };
+
+    Service = {
+      ExecStart = "${pkgs.mako}/bin/mako";
+      Restart = "always";
+      RestartSec = 2;
+    };
+
+    Install.WantedBy = [ sessionTarget ];
+  };
+}