feat(steps): hand pending root steps to a quickshell window

Notification balloons carried the GRUB and homepage root commands, but a
balloon cannot stay open while its commands are pasted into a root shell.
bin/udt-steps NAME writes a consumer's pending steps to
~/.cache/udt/steps/NAME and pokes quickshell's appearance shell, which shows
one tab per file on DP-3. Empty stdin clears the tab, so producers report
on every run and a consumer that caught up drops out by itself.

udt-grub and udt-homepage now route through it. install.sh's SDDM block
checks what is installed and reports only the steps still missing, rather
than printing the full install on every run. udt-homepage remembers the
last staged pair, since udt-accent now also runs on icon switches, which
change neither file and would re-raise the finish steps for nothing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 86 insertions, 31 deletions

diff --git a/bin/udt-grub b/bin/udt-grub
index 20fd296..273389c 100755
--- a/bin/udt-grub
+++ b/bin/udt-grub
@@ -10,8 +10,8 @@
 # and a scheme switch leave the copy stale.
 #
 # udt-accent starts this detached on every run; install.sh runs it in the
-# foreground. A notification goes out only when an installed theme is stale:
-# a machine that never installed it has nothing to refresh.
+# foreground. The root steps go to the steps window through udt-steps, and
+# the tab clears itself once /boot matches the build.
 
 repo="$(dirname "$(readlink -f "$0")")/.."
 grub_repo="$(realpath -m "$repo/../grub-theme-udt")"
@@ -28,23 +28,33 @@ flock 9
 theme=/boot/grub/themes/udt
 copy="rm -rf $theme && cp -r \"$grub_repo/dist/udt\" /boot/grub/themes/"
 
-if diff -rq "$grub_repo/dist/udt" "$theme" >/dev/null 2>&1; then
-    echo "grub theme: up to date"
-elif [ -d "$theme" ]; then
-    echo "grub theme: refresh as root"
+steps() {
+    if diff -rq "$grub_repo/dist/udt" "$theme" >/dev/null 2>&1; then
+        return
+    elif [ -d "$theme" ]; then
+        echo "The GRUB theme was rebuilt. Refresh the copy in /boot as root:"
+    else
+        echo "The GRUB theme is built but not installed. As root:"
+    fi
     echo "  $copy"
-    command -v notify-send >/dev/null 2>&1 &&
-        notify-send -a udt "grub: theme rebuilt" "As root:
-$copy"
-else
-    echo "grub theme: run these as root to install it"
-    echo "  $copy"
-fi
-grep -q "^GRUB_THEME=\"$theme/theme.txt\"" /etc/default/grub 2>/dev/null || {
-    echo "  # once: GRUB_THEME=\"$theme/theme.txt\" in /etc/default/grub, then"
-    echo "  grub-mkconfig -o /boot/grub/grub.cfg"
+    grep -q "^GRUB_THEME=\"$theme/theme.txt\"" /etc/default/grub 2>/dev/null || {
+        echo
+        echo "Once, set GRUB_THEME=\"$theme/theme.txt\" in /etc/default/grub, then:"
+        echo "  grub-mkconfig -o /boot/grub/grub.cfg"
+    }
+    # The panel title falls back to the OS name until one is set.
+    [ -n "$("$repo/bin/udt-machine-name")" ] || {
+        echo
+        echo "Optional, the panel title:"
+        echo "  \"$repo/bin/udt-machine-name\" \"My Machine\""
+    }
 }
-# The panel title falls back to the OS name until one is set.
-[ -n "$("$repo/bin/udt-machine-name")" ] ||
-    echo "  # optional, the panel title: sudo \"$repo/bin/udt-machine-name\" \"My Machine\""
+
+out="$(steps)"
+echo "grub theme: ${out:-up to date}"
+# A theme that was never installed stays out of the steps window: a wallpaper
+# change would otherwise keep asking for an install nobody wanted.
+if [ -d "$theme" ] || [ -z "$out" ]; then
+    printf '%s' "$out" | "$repo/bin/udt-steps" grub
+fi
 exit 0
diff --git a/bin/udt-homepage b/bin/udt-homepage
index 7be5d16..a814d16 100755
--- a/bin/udt-homepage
+++ b/bin/udt-homepage
@@ -4,13 +4,17 @@
 # Licensed under the GNU General Public License v2 only.
 #
 # Staged, not installed: /opt/homepage is root-owned and this script does not
-# hold root there, so it copies into ~/hp-stage/ and a notification carries
-# the command that finishes the job.
+# hold root there, so it copies into ~/hp-stage/ and the steps window
+# (udt-steps) carries the commands that finish the job.
 #
 # udt-accent starts this detached on every run, which covers both a wallpaper
 # change (wallp) and a scheme switch (install.sh). Never slow and never loud
 # when the host is away: a laptop off that network gets a short connect
-# timeout and no notification, since there is nothing for the user to do.
+# timeout and no steps tab, since there is nothing for the user to do.
+#
+# udt-accent also runs for reasons that change neither file, an icon theme
+# switch for one, so what was last staged is remembered and an identical pair
+# is not staged again: the finish steps would reappear for nothing.
 
 repo="$(dirname "$(readlink -f "$0")")/.."
 css="$repo/templates/homepage/custom.css"
@@ -31,6 +35,10 @@ case "$ext" in
 esac
 bg="background.$ext"
 
+stamp="$HOME/.cache/udt/homepage.staged"
+sum="$(cat "$css" "$real" | sha256sum)"
+[ "$sum" = "$(cat "$stamp" 2>/dev/null)" ] && exit 0
+
 scp "${opts[@]}" "$css" homepage:hp-stage/custom.css &&
     scp "${opts[@]}" "$real" "homepage:hp-stage/$bg" || {
     echo "homepage: unreachable, skipped" >&2
@@ -41,13 +49,14 @@ scp "${opts[@]}" "$css" homepage:hp-stage/custom.css &&
 # is not the staging directory, so it is named through the ssh login user,
 # which ssh -G resolves from the config without connecting.
 stage="~$(ssh -G homepage 2>/dev/null | awk '/^user /{print $2}')/hp-stage"
-finish="cp $stage/custom.css /opt/homepage/config/
-cp $stage/$bg /opt/homepage/public/images/
-sed -i 's|/images/background\.[a-z]*|/images/$bg|' /opt/homepage/config/settings.yaml
-systemctl restart homepage"
-echo "homepage: staged, finish as root on homepage:"
-echo "$finish"
-command -v notify-send >/dev/null 2>&1 &&
-    notify-send -a udt "homepage: theme staged" "As root on homepage:
-$finish"
+echo "$sum" > "$stamp"
+out="$(
+    echo "The homepage theme is staged in $stage. Finish as root on homepage:"
+    echo "  cp $stage/custom.css /opt/homepage/config/"
+    echo "  cp $stage/$bg /opt/homepage/public/images/"
+    echo "  sed -i 's|/images/background\\.[a-z]*|/images/$bg|' /opt/homepage/config/settings.yaml"
+    echo "  systemctl restart homepage"
+)"
+echo "$out"
+printf '%s' "$out" | "$repo/bin/udt-steps" homepage
 exit 0
diff --git a/bin/udt-steps b/bin/udt-steps
new file mode 100755
index 0000000..da4aca0
--- /dev/null
+++ b/bin/udt-steps
@@ -0,0 +1,36 @@
+#!/bin/bash
+# udt-steps: hand a consumer's pending manual steps to the steps window.
+# Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+# Licensed under the GNU General Public License v2 only.
+#
+# Usage: <producer> | udt-steps NAME
+#
+# stdin becomes the NAME tab of quickshell's steps window, one file per
+# consumer under ~/.cache/udt/steps/. Empty stdin clears the tab: a consumer
+# that is up to date has nothing to ask for. Either way the running shell is
+# poked over IPC, which reloads the tabs and opens the window when any remain.
+#
+# Format: a line indented two spaces is a command, and a run of them is one
+# block with its own copy button. Everything else is prose. So the root
+# commands producers already printed for a terminal read the same here.
+
+name="${1:?usage: udt-steps NAME}"
+case "$name" in
+    *[!a-z0-9-]*) echo "udt-steps: bad name '$name'" >&2; exit 2 ;;
+esac
+
+dir="$HOME/.cache/udt/steps"
+mkdir -p "$dir"
+text="$(cat)"
+if [ -z "$text" ]; then
+    rm -f "$dir/$name"
+else
+    # Atomic, so the shell never reads half a file.
+    printf '%s\n' "$text" > "$dir/.$name.tmp" && mv "$dir/.$name.tmp" "$dir/$name"
+fi
+
+repo="$(dirname "$(readlink -f "$0")")/.."
+qs_dir="$(realpath -m "$repo/../quickshell/appearance")"
+[ -f "$qs_dir/shell.qml" ] && command -v qs >/dev/null 2>&1 &&
+    timeout 5 qs -p "$qs_dir" ipc call appearance steps >/dev/null 2>&1
+exit 0