chore(release): v1.32.26 — apply the metric/imperial preference across every reading surface

Surface a self-hoster's report that the unit preference was stored but read by
almost no display. Weight, body composition, waist, and temperature now follow
metric or imperial at entry and everywhere they render, storage stays canonical
SI, and the MCP logging tool converts a known unit hint or refuses an unknown
one. OpenAPI diff is version-only; the wire stays canonical.

docs/api/openapi.yaml

@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.32.25
+  version: 1.32.26
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.