fix(scheduled-tasks): edit/duplicate use the task's own timezone, not the account one

A task created in one zone but edited after the account zone changed (or
duplicated) seeded its launch in the task's stored zone while validating and
submitting in the current account zone, drifting unchanged run times. TaskPrefill
now carries the task's timezone; the modal seeds AND submits in it for
edit/duplicate, and only blank creates use the account zone.

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/scheduled-tasks/components/task-modal/task-modal.tsx

@@ -73,6 +73,8 @@ export interface TaskPrefill {
   contexts?: ChatContext[]
   launchDate: string
   launchTime: string
+  /** The task's own zone; the modal seeds AND submits in it so unchanged times never drift. */
+  timezone: string
   recurrence: Recurrence
 }
 
@@ -145,8 +147,9 @@ function TaskModalContent({
   onRequestDelete,
 }: Omit<TaskModalProps, 'open'>) {
   const { workspaceId } = useParams<{ workspaceId: string }>()
-  const timezone = useTimezone()
   const source = edit ?? prefill
+  const accountTimezone = useTimezone()
+  const timezone = source?.timezone ?? accountTimezone
   const editor = usePromptEditor({ workspaceId, initialValue: source?.prompt })
   const setContexts = editor.setContexts
 

apps/sim/app/workspace/[workspaceId]/scheduled-tasks/hooks/use-scheduled-tasks.ts

@@ -149,6 +149,7 @@ export function useScheduledTasks({
         contexts: task.contexts,
         launchDate: zonedWallClock(task.runAt, schedule.timezone).slice(0, 10),
         launchTime,
+        timezone: schedule.timezone,
         recurrence,
       }
     },