feat(quickshell): idle chain, drifting wallpaper, and a few fixes

- Idle is handled in the shell instead of hypridle: the screen dims
  slowly at 4 minutes, locks at 5, powers down at 6, and suspends at 15
  on battery. Idle inhibitors hold every stage off; Super+Shift+I does
  the same by hand and puts a cup on the rail.
- The shell draws the wallpaper (backdrop/), so hyprpaper is gone. The
  picture is drawn a little larger than the screen and drifts with the
  workspace a beat after the windows, and dims a shade while windows are
  open. The path lives in quickshell/wallpaper.
- The lock screen and power menu say "Take your time." instead of the
  NieR slogan.
- hyprpaper is no longer launched twice, the media module keeps the
  player that played last instead of an empty browser tab, and grouped
  windows show thin untitled tabs with their place in the group (2/3)
  in the bar title.
- qt6ct uses Darkly; the package list gains adw-gtk-theme and darkly-bin.

quickshell/README.md

@@ -66,6 +66,7 @@ bar/             the two surfaces and their modules
 popouts/         hover panels hanging off rail and bar modules
 overlays/        power menu, notification toasts, volume/brightness OSD
 lock/            session lock
+backdrop/        the wallpaper, drawn by the shell
 assets/          halftone and stripe tiles, generated with ImageMagick
 ```
 
@@ -143,6 +144,7 @@ Set in `~/.config/hypr/lua/binds/shell.lua`:
 - `Super+Ctrl+L` — lock
 - `Super+P` — power menu
 - `Super+Shift+N` — toggle do not disturb
+- `Super+Shift+I` — stay awake (no dim, lock or screen-off until toggled back)
 - `Super+Ctrl+Shift+N` — clear notifications
 - `Super+A` — ask panel
 - `Super+Shift+R` — reload the shell
@@ -153,6 +155,8 @@ All of these go through Quickshell's IPC, so they work from any script:
 qs ipc call shell lock
 qs ipc call shell power
 qs ipc call shell toggleDnd
+qs ipc call shell toggleStayAwake
+qs ipc call shell wallpaper ~/.wallpapers/space-1.jpg
 qs ipc call shell ask
 qs ipc call shell askAbout "why is the sky blue"
 qs ipc call shell clearNotifications
@@ -211,6 +215,34 @@ NetworkManager for Wi-Fi, UPower for battery, MPRIS for media, and Quickshell's
 own notification server. These are event-driven, so the bar and OSD react the
 instant a volume key is pressed instead of on the next poll.
 
+## Wallpaper
+
+`backdrop/Backdrop.qml` draws it on the background layer; there is no
+hyprpaper. The picture is drawn 8% larger than the screen and drifts with the
+workspace: 1 sits at the top of it and each step down moves it a fixed
+distance, a little slower than Hyprland's own slide, so the windows arrive
+first and the scene behind catches up. It never moves on its own, so an idle
+desktop costs the compositor nothing. While the workspace holds windows it
+settles a shade darker.
+
+The choice is one line in `quickshell/wallpaper` (`~` allowed), watched live.
+`qs ipc call shell wallpaper <path>` rewrites it.
+
+## Idle
+
+`services/Idle.qml`, on Wayland's idle-notify protocol instead of hypridle:
+
+| After | Does |
+|---|---|
+| 4 min | the screen dims slowly (`overlays/IdleDim.qml`); any input lifts it |
+| 5 min | lock |
+| 6 min | displays off; any input wakes them |
+| 15 min | suspend, on battery only |
+
+Every stage respects idle inhibitors, so a fullscreen video holds them all
+off. `Super+Shift+I` does the same by hand and puts a cup on the rail while it
+is on.
+
 ## Lock screen
 
 Authenticates through `/etc/pam.d/hyprlock`, which on this box is just
@@ -219,7 +251,8 @@ styled in an ordinary window (`qs -p lockpreview.qml`) without locking the
 session.
 
 It is the wallpaper, barely softened, with the face set in the dark of the
-porthole: the mark, the time in light display type, the date, a status log
+porthole: the mark, the time in light display type, the date, "Take your
+time.", a status log
 (battery, network, what is playing, unread notices), and a rounded field that
 fills with dots as you type. The dots breathe while PAM checks; a wrong
 password turns them and the field's rim to rust and nudges the field once.
@@ -231,6 +264,9 @@ means restarting Hyprland from a TTY.
 ## What was retired
 
 - `waybar.service` — disabled. Its config is still in `~/.config/waybar`.
+- `hyprpaper` — replaced by `backdrop/`. Turn its unit off with
+  `systemctl --user disable --now hyprpaper`.
+- `hypridle` — never installed; `services/Idle.qml` does the job.
 - `dunst.service` — masked, so it cannot be D-Bus activated and steal
   `org.freedesktop.Notifications`. Undo with
   `systemctl --user unmask dunst.service`.
@@ -311,8 +347,9 @@ network and bluetooth, but keep running as the secret and pairing agents.
   the opening's 18px corners at a 10px gap (`Theme.frameRadius - gaps_out`);
   change one and the others follow. No blur, both opacities at `1.0`, 1px
   borders running from the light into the suit's grey. The shadow is soft and
-  wide, so windows float in the opening. Group tabs are solid hull slabs, the
-  current one lifted a step with its title in the light. Motion
+  wide, so windows float in the opening. Group tabs are thin rounded lines with
+  no titles, the current one in the light; the bar writes the title once and
+  adds the window's place in the group (`2/3`). Motion
   (`hypr/lua/animations.lua`) glides and settles with no overshoot: windows
   resolve in from a hair smaller, workspaces drift a short way vertically and
   fade (sliding behind the hull), the `SUPER+S` scratchpad lowers out from
@@ -335,7 +372,8 @@ network and bluetooth, but keep running as the secret and pairing agents.
   The theme name is also in `xsettingsd/xsettingsd.conf` and has to be set with
   `gsettings` for portal-aware apps.
 - **Qt** — qt6ct with `qt6ct/colors/yorha.conf`, the same palette in
-  `QPalette` roles. The style is Fusion unless Darkly is installed.
+  `QPalette` roles, drawn with the Darkly style (package `darkly-bin`) for
+  rounded controls. Fusion is the fallback if Darkly is missing.
 - **zathura** — `zathura/yorha`, included from `zathurarc`. Pages are
   recoloured onto the hull with text in bone; images keep their colours.
   Search hits are a soft bone wash, and the current hit is sand.