chore(release): v1.28.54 — one hero on the dashboard

Retires the legacy opt-in dashboard hero now that the Today view leads the
dashboard, so the two never stack. Removes the hero mount, its skeleton, the
carousel/spotlight components only it rendered, and the heroVisible layout
field (a stored layout that still carries it is ignored on read, never
re-persisted, so nothing to migrate). The greeting is now always shown. The
mobile-density guard measures the Today hero.

The score-ring selection stays in the layout contract for the native client;
its web picker is a follow-up decision (resurface in the Today view or leave it
native-only).

docs/api/openapi.yaml

@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.28.53
+  version: 1.28.54
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.