feat: platform backbone and field capture, first part (checkpoint)

Platform backbone (plan 2026-10-13-plattform-rueckgrat), reviewed tasks:
- run roles api/worker/job/all with shared startup checks (Task 1)
- schema and migration for DomainEvent, deliveries, JobRun, ThrottlerHit (Task 2)
- audit, notifications and domain events written in the same transaction (Task 3)
- dispatcher with SKIP LOCKED claims, retries and stale release (Task 4)
- worker building blocks: tick, LISTEN/NOTIFY wake-up, health (Task 5)
- worker process and entry points (Task 6)
- throttler counters in Postgres (Task 19)
- separate keys per purpose with key ring (Task 20)
- public origin page without exact location (Task 22)
- shop keys split into read and write (Task 23)
- Kustomize base, components, overlay encry, CI validation (Task 26)

Field capture T3 (plan 2026-10-13-t3-erfassung-am-stand), reviewed tasks:
- brood frames, read endpoints, apiary overview and offline pack
- network basics, offline queue v3, navigation sheets, form building blocks
- new inspection with last-time hints and weather, varroa per day,
  treatment prefill, apiary page with round
- inspection photo (Task 10) is implemented, review pending

Not rolled out. Remaining tasks follow in later commits.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Frontend/src/components/treatments/prefill-note.tsx

@@ -0,0 +1,18 @@
+/** Visible note that a value is a suggestion and not something the user entered. */
+export function PrefillNote({ id, source }: { id: string; source: string | undefined }) {
+  if (!source) return null;
+  return (
+    <p id={`${id}-prefill`} className="text-xs font-medium text-muted-foreground">
+      aus letzter Behandlung mit {source}
+    </p>
+  );
+}
+
+/** The control's aria-describedby, extended by the prefill note when one is shown. */
+export function describedByWith(
+  id: string,
+  describedBy: string | undefined,
+  source: string | undefined,
+): string | undefined {
+  return [describedBy, source ? `${id}-prefill` : undefined].filter(Boolean).join(" ") || undefined;
+}