fix(#470): replace em-dash in apply comment (CI em-dash guard #464)

The #470 comment used an em-dash, failing the analyze job's no-em-dash guard.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/services/observer_apply_service.dart

@@ -40,7 +40,7 @@ class ObserverApplyService {
     for (final b in writes.brokers) {
       // Import NEVER touches enabled state (#470, owner directive): a config
       // import carries no enabled/disabled, and the firmware already force-
-      // disables a slot on any field write (#53). We do not re-enable — the slot
+      // disables a slot on any field write (#53). We do not re-enable; the slot
       // is left DISABLED and the operator re-enables intentionally. Prior enabled
       // state is not carried over.
       final res = await _svc.saveBroker(