Reach the coturn self-heal check from asterisk.sh's update path too

Direct follow-up to the previous commit's ensure_coturn_user() fix: that
fix is useless for Asterisk specifically unless something actually calls
ensure_coturn_user("asterisk") again, and the update ("Reinstall in
place") branch returns 0 well before the fresh-install path's call to it
— only "Full install" reached it, which re-prompts everything (droplet
detection, domain, etc.) just to fix a credential re-registration.

Added the same call to the update path, gated on NOT having an embedded
coturn (checked via the existing _HAD_EMBEDDED_COTURN detection) — calling
it unconditionally would silently chain-install the shared coturn service
for a box deliberately running Asterisk's own dedicated coturn, exactly
the kind of silent update-time migration CLAUDE.md's coturn guidance
warns against. .env stays untouched either way (self-heal re-registers
with the same cached password, never generates a new one).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H4k6J1qXXyYxhGEgnJaMvn

services/asterisk.sh

@@ -1655,6 +1655,21 @@ install_asterisk() {
                     log_warning "docker compose up failed — check: docker compose -f $EA_DIR/docker-compose.yml logs"
                 fi
 
+                # Self-heal a stale/orphaned shared-coturn registration on
+                # every update, not just a full reinstall — the check inside
+                # ensure_coturn_user() is what actually re-registers a
+                # missing user, this just needs to reach it. Gated on NOT
+                # having an embedded coturn: an install with its own
+                # dedicated coturn deliberately never touches the shared one
+                # on update (see the warning above and CLAUDE.md's coturn
+                # migration guidance) — calling this unconditionally would
+                # silently chain-install services/coturn.sh for a box that
+                # was never using it, the exact "don't migrate silently on
+                # update" mistake that guidance warns against.
+                if [[ "$_HAD_EMBEDDED_COTURN" != true ]]; then
+                    ensure_coturn_user "asterisk"
+                fi
+
                 _asterisk_run_presence_step "$EA_DIR" "$CONTAINER"
                 _asterisk_offer_dashboard_and_trunk "$EA_DIR"