chore(release): v1.21.2

Surfaces the Coach's existing intelligence as ambient presence: a per-metric
"Coach read", a visible scope handoff and a seeded opener, briefing callbacks,
a tension verdict and return-to-baseline note on the score, two motivational-
interviewing moves, and grounding parity on the local model path. No
migrations, no breaking changes.

docs/api/openapi.yaml

@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.21.1
+  version: 1.21.2
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.