fix(webapp): resume syncs the fresh row's limit and honors a zero limit

Resume writes the engine limit from the row the update returned, so a
concurrent deploy's change is not overwritten with a stale snapshot,
and a declared limit of zero is written as zero instead of removing
the limit and leaving the queue uncapped.

Author: matt-aitken

apps/webapp/app/v3/services/pauseQueue.server.ts

@@ -57,11 +57,20 @@ export class PauseQueueService extends BaseService {
         },
       });
 
+      /**
+       * Resume syncs from the row the update returned, never the pre-update
+       * snapshot, so a limit changed by a concurrent deploy is not resurrected.
+       * A declared limit of zero is a real limit and must be written, not removed.
+       */
       if (action === "paused") {
         await updateQueueConcurrencyLimits(environment, queue.name, 0);
       } else {
-        if (queue.concurrencyLimit) {
-          await updateQueueConcurrencyLimits(environment, queue.name, queue.concurrencyLimit);
+        if (typeof updatedQueue.concurrencyLimit === "number") {
+          await updateQueueConcurrencyLimits(
+            environment,
+            queue.name,
+            updatedQueue.concurrencyLimit
+          );
         } else {
           await removeQueueConcurrencyLimits(environment, queue.name);
         }