notices: add the created/updated fields everything sorts by

The collection was declared with exactly the fields it needs -- message,
active, endsAt -- and PocketBase adds no created/updated unless asked.
Both readers sort by -created, so both got 400 for the life of the
feature: the app's NoticeService caught it and swallowed it, and the
dashboard's own listing showed 'zatím žádné' however many notices
existed. Writing worked throughout; nothing could read what was written.

Additive and reversible. created is onCreate only; updated moves on every
save, which costs nothing and is what a pull cursor wants.

pb_migrations/1793500000_notices_autodate.js

@@ -0,0 +1,36 @@
+/// <reference path="../pb_data/types.d.ts" />
+
+// Give `notices` the `created` field everything already sorts by.
+//
+// The collection was declared with exactly the fields it needs -- message,
+// active, endsAt -- and PocketBase does not add `created`/`updated` unless they
+// are asked for. Both readers ask for `sort=-created`:
+//
+//   - the app's NoticeService, which caught the resulting 400 and swallowed it,
+//     so a notice never appeared and nothing said why;
+//   - the status dashboard's own listing, which therefore always showed "zatím
+//     žádné" no matter how many notices existed.
+//
+// So the feature had never once worked end to end, and the failure was
+// invisible from both ends. Writing worked; nothing could read what was written.
+//
+// `onCreate` only for `created`; `updated` moves on every save, which is what a
+// pull cursor wants and costs nothing here.
+migrate(
+  (app) => {
+    const c = app.findCollectionByNameOrId("notices");
+    c.fields.add(
+      new Field({ type: "autodate", name: "created", onCreate: true, onUpdate: false }),
+    );
+    c.fields.add(
+      new Field({ type: "autodate", name: "updated", onCreate: true, onUpdate: true }),
+    );
+    app.save(c);
+  },
+  (app) => {
+    const c = app.findCollectionByNameOrId("notices");
+    c.fields.removeByName("created");
+    c.fields.removeByName("updated");
+    app.save(c);
+  },
+);