Background selector (#4519)

* UPDATE: select background method

* ADD: migration file for background selector

* Add symlink for background selector in walker-elephant.sh

Forgot about this file. Should be added to make sure the background selector feature available in the fresh install

* clean up the code a bit

Updated omarchy background selector to hide from provider list and removed subtext from entries.

* Make the background selector the default

* Fix migration

* FIX: typo on background symlink target

* UPDATE: add ~/.config/omarchy/backgrounds/theme.name

* UPDATE: Cache = false

* Fix escaping for all extensions

* Extract omarchy-theme-bg-set

---------

Co-authored-by: David Heinemeier Hansson <david@hey.com>

bin/omarchy-theme-bg-set

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Sets the specified image as the current background
+
+if [[ -z "$1" ]]; then
+  echo "Usage: omarchy-theme-bg-set <path-to-image>" >&2
+  exit 1
+fi
+
+BACKGROUND="$1"
+CURRENT_BACKGROUND_LINK="$HOME/.config/omarchy/current/background"
+
+# Create symlink to the new background
+ln -nsf "$BACKGROUND" "$CURRENT_BACKGROUND_LINK"
+
+# Kill existing swaybg and start new one
+pkill -x swaybg
+setsid uwsm-app -- swaybg -i "$CURRENT_BACKGROUND_LINK" -m fill >/dev/null 2>&1 &