chore(release): v1.28.12 — lab scans use your AI provider; tidier dashboard

Lab-report scanning now uses the configured AI provider, rasterizing a scanned
PDF to images for any non-Anthropic vision provider (parity with the document
vault). Removes the separate lab-scan provider setting and its columns
(migration 0234). The overdue-medication log action stacks directly under its
line on the dashboard instead of far to the right.

docs/api/openapi.yaml

@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.28.11
+  version: 1.28.12
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.