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

install.sh

@@ -15,7 +15,11 @@
 # Migrated so far, grouped the same way the legacy menu groups them:
 #   Core Settings: Sites & Page Timing, Display & Interaction, Timezone,
 #     Hidden Site PIN, Password Protection & Lockout, WiFi,
-#     Power/Display/Quiet Hours.
+#     Power/Display/Quiet Hours, Complete Uninstall
+#     (menus/complete_uninstall.sh - composed from every addon's own
+#     uninstall helper rather than re-implementing removal a second
+#     time; Upgrade and Full Reinstall stay in the legacy script, both
+#     coupled to its heredoc self-extraction of main.js/preload.js/etc).
 #   Addons: CUPS Printing (menus/addon_cups.sh), Authelia Auto-Login
 #     (menus/addon_authelia.sh), Remote Access - VNC/WireGuard/
 #     Tailscale/Netbird (menus/addon_remote_access.sh), LMS Server /
@@ -76,6 +80,10 @@ source "$SCRIPT_DIR/menus/advanced_factory_reset.sh"
 source "$SCRIPT_DIR/menus/advanced_virtual_consoles.sh"
 # shellcheck source=menus/advanced_emergency_hotspot.sh
 source "$SCRIPT_DIR/menus/advanced_emergency_hotspot.sh"
+# shellcheck source=menus/complete_uninstall.sh
+# Sourced last: composes the *_do_uninstall/*_do_remove_all/*_do_disable
+# helpers defined in every file above it.
+source "$SCRIPT_DIR/menus/complete_uninstall.sh"
 
 ################################################################################
 # Preflight
@@ -122,6 +130,7 @@ core_settings_menu_builder() {
         "Password Protection & Lockout"
         "WiFi"
         "Power/Display/Quiet Hours"
+        "Complete Uninstall"
     )
     MENU_HANDLERS=(
         sites_menu
@@ -131,6 +140,7 @@ core_settings_menu_builder() {
         lockout_menu
         wifi_menu
         power_schedule_menu
+        complete_uninstall_menu
     )
 }