Migrate Complete Uninstall, composed from each addon's own uninstall helper; bump to v2.12.0

New menus/complete_uninstall.sh (Core Settings), the last of the
"destructive trio". Rather than re-implementing every addon's teardown
a second time (the legacy shape), it composes the *_do_uninstall
helpers each addon already has - if an addon's removal logic changes,
Complete Uninstall picks it up automatically.

Every addon menu with an uninstall action (CUPS, VNC, WireGuard,
Tailscale, Netbird, LMS, Squeezelite, Asterisk Intercom) plus
power_schedule's "remove all schedules" and Emergency Hotspot's disable
action were each split into a confirm-and-call wrapper (unchanged from
the user's perspective) and a silent do-the-removal helper that both
the wrapper and Complete Uninstall call.

Bug fix found while composing these: several *_do_uninstall helpers
(CUPS's apt autoremove/apt clean, VNC/WireGuard/Tailscale/Netbird's apt
remove) had a bare, unguarded apt call as their second-to-last
statement. Previously this only risked aborting that one menu action if
the package was already gone. Composed together as sequential calls
inside Complete Uninstall, the same failure would have silently
truncated the entire uninstall sequence partway through. Guarded all of
them with `|| true`.

Non-addon teardown (kiosk user/files, Node.js, LightDM/Openbox,
remaining systemd units/scripts, polkit rules, re-enabling virtual
consoles, final package cleanup) stays inline in
menus/complete_uninstall.sh, since no single addon owns those paths.

Upgrade and Full Reinstall stay in ubuntu-based-kiosk.sh only - both
are coupled to its own heredoc self-extraction of main.js/preload.js/
etc, which has no modular equivalent yet.

Full command-level stubbed test suite exercising the full 12-step
teardown, confirmation-text validation, and reboot prompt. Full
19-suite regression + real end-to-end menu navigation via install.sh
all pass.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VfsFSoRqfbRG7XAg5RoE7e

menus/addon_lms_squeezelite.sh

@@ -194,6 +194,16 @@ action_install_lms() {
 action_uninstall_lms() {
     echo
     ask_yes_no "Remove LMS Server?" "n" || { echo "Cancelled"; pause; return; }
+    lms_do_uninstall ask
+    pause
+}
+
+# The actual removal, no confirmation prompt - shared with Complete
+# Uninstall so that operation doesn't need to re-implement LMS teardown a
+# second time. $1: "ask" to prompt about data removal interactively (the
+# normal case), "purge" to remove data without asking (Complete Uninstall).
+lms_do_uninstall() {
+    local data_choice="${1:-ask}"
 
     local service_name
     service_name=$(lms_service_name)
@@ -212,15 +222,20 @@ action_uninstall_lms() {
     sudo rm -f /etc/apt/sources.list.d/lms.list
     sudo rm -f /usr/share/keyrings/lms-keyring.gpg
 
-    if ask_yes_no "Remove LMS data and configuration?" "n"; then
+    local purge_data=false
+    if [[ "$data_choice" == "purge" ]]; then
+        purge_data=true
+    elif [[ "$data_choice" == "ask" ]] && ask_yes_no "Remove LMS data and configuration?" "n"; then
+        purge_data=true
+    fi
+
+    if $purge_data; then
         sudo rm -rf /var/lib/squeezeboxserver
         sudo rm -rf /etc/squeezeboxserver
         log_success "LMS and data removed"
     else
         log_success "LMS removed (data preserved)"
     fi
-
-    pause
 }
 
 ################################################################################
@@ -332,13 +347,16 @@ EOF
 action_uninstall_squeezelite() {
     echo
     ask_yes_no "Remove Squeezelite Player?" "n" || { echo "Cancelled"; pause; return; }
+    squeezelite_do_uninstall
+    pause
+}
 
+# Shared with Complete Uninstall - same reasoning as lms_do_uninstall.
+squeezelite_do_uninstall() {
     sudo systemctl stop squeezelite 2>/dev/null || true
     sudo systemctl disable squeezelite 2>/dev/null || true
     sudo rm -f "$SYSTEMD_DIR/squeezelite.service"
     sudo rm -f "$BIN_DIR/squeezelite-start.sh"
     sudo apt remove -y squeezelite 2>/dev/null || true
     log_success "Squeezelite removed"
-
-    pause
 }