Remove waybar; relocate bar helper scripts into the shell tree

omarchy-shell's bar plugin replaces waybar on every default path, so the
waybar package, configs, indicator scripts, and toggle/restart/refresh
binaries all go away in this commit.

The four small helper scripts that Bar.qml shells out to (weather.sh and
indicators/*.sh) move with the shell rather than disappear \u2014 they live
at default/quickshell/omarchy-shell/scripts/ now, alongside the rest of
the shell code.

Companion script changes:
  - omarchy-shell-ipc gains --if-running so fire-and-forget refresh
    callers (toggle-idle, toggle-notification-silencing,
    update-available-reset, capture-screenrecording) don't accidentally
    spawn the shell when it isn't already up.
  - omarchy-theme-set, omarchy-tz-select, omarchy-voxtype-{install,model},
    omarchy-toggle-nightlight, omarchy-voxtype-config drop their waybar
    branches and comments.
  - omarchy-voxtype-status's summary stops claiming it's a Waybar helper.
  - omarchy-base.packages drops waybar; install/packaging/fonts.sh's
    comment points at the new bar consumer.
  - SKILL.md / AGENTS.md / omarchy-menu.jsonc lose their waybar entries.
  - test/omarchy-cli-test.sh substitutes a remaining toggle command.

test/omarchy-cli-test.sh

@@ -88,7 +88,7 @@ assert_output_contains "bare group includes browser route" "$output" "omarchy in
 
 output=$("$CLI" toggle)
 assert_output_contains "bare root command with children renders help" "$output" "Toggle commands"
-assert_output_contains "bare toggle help includes child route" "$output" "omarchy toggle waybar"
+assert_output_contains "bare toggle help includes child route" "$output" "omarchy toggle nightlight"
 
 output=$("$CLI" pkg --help)
 assert_output_contains "package group includes pkg add fallback route" "$output" "omarchy pkg add <packages...>"