Scheduled-result notifications: first lines, Open / Run again / Pause; a click opens

A run's own notification (run.notification, server dev) gives the body (the
result's first lines) and the actions with labels in the person's language;
they become the notification's action type. Every notification is
remembered by id (watch::Notes) so a click opens the chat or the task, and
Run again / Pause post /schedules/{id}/run|pause without the window. An
older server's run is said as before. Fixtures re-pinned at server dev
e0c2332, schedule.json added.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/ui/fixtures/event_schedules.json

@@ -1,5 +1,5 @@
 {
-  "version": "d2f307bf1c7b8d6b",
+  "version": "8bee85746004dc19",
   "schedules": [
     {
       "id": "sched1",
@@ -52,6 +52,7 @@
       "fired_count": 3,
       "failure_streak": 0,
       "watch": null,
+      "runs_on": null,
       "last_error": null,
       "last_run": {
         "id": "run1",