feat(hypr): add non-locking idle blanker

Blank all displays after five minutes without using DPMS or locking the session.

.config/hypr/hypridle.conf

@@ -0,0 +1,6 @@
+# Non-locking Wayland screen blanker. It covers every monitor in black and
+# dismisses itself on any key press or mouse click; it never changes DPMS.
+listener {
+    timeout = 300
+    on-timeout = /home/alex/.local/bin/wayshell-blanker
+}

.config/hypr/machine.lua##class.arch_desktop

@@ -10,6 +10,7 @@ return {
   },
   startup = {
     "noctalia",
+    "hypridle",
     -- Electron's tray icon registers only when the SNI watcher already exists.
     "sh -c 'sleep 2; exec mullvad-vpn'",
     "thunderbird",