chore(release): v1.28.9 — document chat in the coach dialog

Chatting about a document opens the coach chat dialog scoped to that document,
entered from a neutral icon in the document's top-right (matching insights),
instead of a separate inline panel. The document chat's stricter footing is
unchanged — one document only, no health-record context, no tools, plain text.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "healthlog",
-  "version": "1.28.8",
+  "version": "1.28.9",
   "description": "Self-hosted personal-health-tracking PWA with Withings integration, AI insights, and doctor-report PDF export.",
   "license": "PolyForm-Noncommercial-1.0.0",
   "homepage": "https://healthlog.dev",