chore(release): v1.9.0 — Insights time-ranges, deeper mood, medication coding, stability

Insights gain selectable time ranges with period-over-period deltas, and the
mood page adds time-of-day, stability and weight/BP correlation reads. Medications
can carry ATC + RxNorm codes that flow into the health-record export alongside a
MedicationAdministration per acted dose. The connection pool is sized for real
concurrency to remove the under-load stalls, and the medication advanced-settings
page is rebuilt. The standalone /targets page is retired in favour of inline editing.

docs/api/openapi.yaml

@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.8.7.1
+  version: 1.9.0
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.