feat(quickshell): replace fuzzel with an in-process launcher

fuzzel could only answer "which app", so launching Brave at a URL meant
picking the app, waiting for it, then typing the address somewhere else.
The launcher now takes a verb and an object in one line: type
`gitlab.enqs.de` and every app that can open it sorts to the top, default
browser first, ready for Enter — or arrow/hjkl down to Brave's New
Incognito Window, which is offered as a peer of Brave itself rather than
hidden behind a submenu.

services/Apps.qml is the brain and holds no UI: it flattens desktop
entries and their actions into one index, classifies the typed argument
(url / mail / path), ranks by fuzzy match plus handler affinity plus
frecency, and launches. Launching through `uwsm app` keeps each app in its
own scope; entries whose Exec declares no field code (Brave's
`--incognito` action, among others) are launched by tokenising Exec per
the Desktop Entry spec and appending the argument, never via `sh -c`.

Four prefixes reuse the same window, so there is one picker and one set of
keys: `>` runs a command, `=` evaluates arithmetic, `:` is clipboard
history (cliphist, which had been a second fuzzel invocation), and a
dmenu mode is driven over IPC.

quickshell/scripts/takemi-dmenu is the bridge for that last one — a
`fuzzel --dmenu` drop-in for scripts that want a picker, symlinked into
~/.local/bin. fluxo's bt menu now goes through it.

Living in the Quickshell process means the window is on screen on the
frame the bind fires, with no process to spawn.

Removes fuzzel entirely: its config, its theme submodule, the package,
and the last consumers (the bar sigil, fluxo's menu_command). Also drops
hypr/scripts/powermenu.sh, which was fuzzel-based and bound to nothing.

quickshell/scripts/takemi-dmenu

@@ -0,0 +1,39 @@
+#!/bin/sh
+# fuzzel --dmenu, backed by the Takemi launcher in Quickshell.
+#
+# Reads choices on stdin, prints the chosen line on stdout, prints nothing if
+# the launcher was dismissed. Accepts the handful of fuzzel flags the callers
+# in this config actually pass so they did not have to be rewritten.
+#
+# The launcher lives in the already-running shell process, so unlike fuzzel
+# there is nothing to start; the cost here is the two-file handshake, which
+# exists because `qs ipc call` returns immediately and a dmenu has to block.
+set -eu
+
+prompt=""
+while [ $# -gt 0 ]; do
+    case "$1" in
+        --dmenu|-d) ;;
+        --prompt) prompt="${2-}"; shift ;;
+        --prompt=*) prompt="${1#--prompt=}" ;;
+        *) ;;
+    esac
+    shift
+done
+
+dir=$(mktemp -d)
+trap 'rm -rf "$dir"' EXIT INT TERM
+cat > "$dir/in"
+
+qs ipc call shell dmenu "$dir/in" "$dir/out" "$prompt" >/dev/null
+
+# Give up after two minutes rather than wedging a caller forever if the shell
+# is reloaded out from under us mid-choice.
+i=0
+while [ ! -e "$dir/out" ]; do
+    i=$((i + 1))
+    [ "$i" -gt 2400 ] && exit 1
+    sleep 0.05
+done
+
+cat "$dir/out"