chore(release): v1.38.5 — the backup finishes, the dashboard stops scanning

Carries the night's audit work: the weekly backup ran out of memory
rather than out of time and now completes, two dashboard reads stopped
scanning the largest tables, six webhook verbs compare a secret behind a
rate limit, three global channel switches actually stop delivery,
thirty-five settings reach the container, four guarded helpers are used
where their naive twins were, and three guards now see what they claim.

docs/api/openapi.yaml

@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.38.4
+  version: 1.38.5
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.