Calendar view shows duplicate date links for objects that exist only once

Space: HSKD (2a0980bb-7cc7-4870-8a9c-b48984ce9939)

In the calendar / "Datumsverlinkungen" view, every object of my custom type "Gitarren–Unterricht" appears twice. Example: 19 Aug 2026, 14:30–15:00, "UE Erik Schellenberger Costa" is listed twice.

The duplicates appear on macOS and iOS, so this is not a local cache issue. Server state says the objects exist only once. Verified three ways via the API:

• GET /objects/structure?id=282c6acd-6034-4474-b3e1-01ac7ff6bc63 returns 30 objects, all unique ids, one per time slot
• POST /objects/search for "Erik Schellenberger" returns exactly 2 objects (7c1ae8e2… for 19 Aug, 5c276e3b… for 26 Aug) — one per week, as expected
• GET /object on each id confirms one object per slot

The trash is empty.

Likely cause: on 19 Aug I replaced 23 objects of this type via the API — created new ones, then deleted the old ones with DELETE /object?hardDelete=true. The deleted ids now return 404 for GET, DELETE and PATCH, so they are gone. But the date-link index still renders them: the phantom rows show the OLD body structure of the deleted objects, while the real objects show the current one.

So the date-link index appears to retain entries for hard-deleted objects. Rewriting the date property of an affected object with an identical value (PATCH /object) did not clear the phantom entry. Could you rebuild the date-link index for this space?