chore(release): v1.28.4 — medication efficacy

Per-medication effect view: plots the target metric/lab with start, dose
changes, and pauses marked, a before/after-start comparison, and adherence
overlaid — descriptive only, never a verdict or dose advice. Compact summary on
the medication insights area. Target resolved from ATC class or name, with a
per-user override. Migration 0232.

docs/api/openapi.yaml

@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.28.3
+  version: 1.28.4
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.