feat(webapp): resolve env-level default region in trigger path

getDefaultWorkerGroupForProject now checks the environment default before
the project default. Adds resolveEffectiveDefaultWorkerGroupId as the shared
fallback chain (env -> project -> global).

Author: myftija

apps/webapp/app/runEngine/concerns/queues.server.ts

@@ -389,6 +389,7 @@ export class DefaultQueueManager implements QueueManager {
     const [error, workerGroup] = await tryCatch(
       workerGroupService.getDefaultWorkerGroupForProject({
         projectId: environment.projectId,
+        environmentDefaultWorkerGroupId: environment.defaultWorkerGroupId,
         regionOverride,
       })
     );

apps/webapp/app/v3/regionAccess.server.ts

@@ -33,6 +33,29 @@ export function defaultVisibilityFilter(
   return { hidden: false, workloadType: { not: "MICROVM" } };
 }
 
+/**
+ * Canonical fallback chain for a run's default region:
+ * environment default -> project default -> global default.
+ * Both the trigger path and the regions UI must use this order so the
+ * displayed default matches what actually runs.
+ */
+export function resolveEffectiveDefaultWorkerGroupId({
+  environmentDefaultWorkerGroupId,
+  projectDefaultWorkerGroupId,
+  globalDefaultWorkerGroupId,
+}: {
+  environmentDefaultWorkerGroupId?: string | null;
+  projectDefaultWorkerGroupId?: string | null;
+  globalDefaultWorkerGroupId?: string | null;
+}): string | undefined {
+  return (
+    environmentDefaultWorkerGroupId ??
+    projectDefaultWorkerGroupId ??
+    globalDefaultWorkerGroupId ??
+    undefined
+  );
+}
+
 /**
  * Whether a region is accessible given compute access.
  * MICROVM regions require compute access; all other types pass through.

apps/webapp/app/v3/services/worker/workerGroupService.server.ts

@@ -220,9 +220,11 @@ export class WorkerGroupService extends WithRunEngine {
 
   async getDefaultWorkerGroupForProject({
     projectId,
+    environmentDefaultWorkerGroupId,
     regionOverride,
   }: {
     projectId: string;
+    environmentDefaultWorkerGroupId?: string | null;
     regionOverride?: string;
   }): Promise<WorkerInstanceGroup | undefined> {
     const project = await this._prisma.project.findFirst({
@@ -282,6 +284,18 @@ export class WorkerGroupService extends WithRunEngine {
       return workerGroup;
     }
 
+    // Resolution order must match resolveEffectiveDefaultWorkerGroupId:
+    // environment default -> project default -> global default.
+    if (environmentDefaultWorkerGroupId) {
+      const envWorkerGroup = await this._prisma.workerInstanceGroup.findFirst({
+        where: { id: environmentDefaultWorkerGroupId },
+      });
+
+      if (envWorkerGroup) {
+        return envWorkerGroup;
+      }
+    }
+
     if (project.defaultWorkerGroup) {
       return project.defaultWorkerGroup;
     }