fix(webapp): anchor schedules-list lastRun on updatedAt, not createdAt

ScheduleListPresenter was guarding the cron-derived lastRun against
schedule.createdAt, which only proves the row exists. If a schedule
was edited (cron changed, timezone changed) or deactivated and then
reactivated, the cron's previous slot might predate the most recent
config change but still pass the createdAt guard — surfacing a
"Last run" the schedule never actually fired at under the current
configuration.

Switch the guard to schedule.updatedAt. Prisma's @updatedat bumps on
every row update (cron change, timezone change, activate toggle, etc.),
so the cron-derived slot is only shown once it's strictly after the
most recent config change — meaning the current config has been in
effect long enough to have actually fired at that slot.

Per CodeRabbit review on PR #3476.

Author: ericallam

apps/webapp/app/presenters/v3/ScheduleListPresenter.server.ts

@@ -197,6 +197,7 @@ export class ScheduleListPresenter extends BasePresenter {
         },
         active: true,
         createdAt: true,
+        updatedAt: true,
       },
       where: {
         projectId: project.id,
@@ -249,19 +250,21 @@ export class ScheduleListPresenter extends BasePresenter {
       // Approximate "last run" from the cron's previous slot. Skip inactive
       // schedules — the cron's previous slot reflects what *would* have
       // fired, but a deactivated schedule didn't actually fire there. Skip
-      // schedules whose cron's previous slot predates their creation — the
-      // schedule hasn't existed long enough to have fired. cron-parser
-      // throws on malformed expressions, so degrade to undefined per-row
-      // rather than failing the whole list. UI is best-effort; the runs
-      // page is the source of truth.
+      // when the cron's previous slot predates `updatedAt`: any config
+      // change (cron edited, timezone changed, deactivate/reactivate)
+      // bumps updatedAt, and a slot from before the most recent change
+      // didn't fire under the current configuration. cron-parser throws
+      // on malformed expressions, so degrade to undefined per-row rather
+      // than failing the whole list. UI is best-effort; the runs page is
+      // the source of truth.
       let lastRun: Date | undefined;
       if (schedule.active) {
         try {
           const cronPrev = previousScheduledTimestamp(
             schedule.generatorExpression,
             schedule.timezone
           );
-          lastRun = cronPrev.getTime() > schedule.createdAt.getTime() ? cronPrev : undefined;
+          lastRun = cronPrev.getTime() > schedule.updatedAt.getTime() ? cronPrev : undefined;
         } catch {
           lastRun = undefined;
         }