fix: address PR review thread issues

Agent-Logs-Url: https://github.com/devitq/movienight-backend/sessions/d4d6ebbb-2508-484e-accf-c891be54750f

Co-authored-by: devitq <118541411+devitq@users.noreply.github.com>

src/main/kotlin/com/project/movienight/adapters/web/JellyfinEventsController.kt

@@ -27,6 +27,10 @@ class JellyfinEventsController(
         @RequestHeader(value = "X-MovieNight-Plugin-Token", required = false) token: String?,
         @RequestBody request: JellyfinEventRequest,
     ) {
+        if (!properties.enabled) {
+            throw ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Jellyfin integration is disabled")
+        }
+
         if (properties.pluginToken.isNotBlank()) {
             if (token == null || token != properties.pluginToken) {
                 throw ResponseStatusException(HttpStatus.UNAUTHORIZED, "Invalid plugin token")