feat(schedules): add timezone support for scheduled jobs and update database schema

- Introduced a new `commonTimezones` array for timezone selection in the UI.
- Updated the schedule form to include an optional timezone field.
- Modified the database schema to add a `timezone` column to the `schedule` table.
- Enhanced the scheduling logic to utilize the specified timezone, defaulting to UTC if not provided.

apps/schedules/src/schema.ts

@@ -15,6 +15,7 @@ export const jobQueueSchema = z.discriminatedUnion("type", [
 		cronSchedule: z.string(),
 		type: z.literal("schedule"),
 		scheduleId: z.string(),
+		timezone: z.string().optional(),
 	}),
 	z.object({
 		cronSchedule: z.string(),