chore(release): bump package.json to 1.4.38.4

Mirrors the v1.4.38.4 tag (the previous release commit only carried
the CHANGELOG entry because the editor lost the version-line edit on
a merge race). `NEXT_PUBLIC_APP_VERSION` derives from this string at
build time, so the running shell's self-heal poll would otherwise
keep firing against itself.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "healthlog",
-  "version": "1.4.38.3",
+  "version": "1.4.38.4",
   "description": "Self-hosted personal-health-tracking PWA with Withings integration, AI insights, and doctor-report PDF export.",
   "license": "AGPL-3.0-only",
   "homepage": "https://healthlog.dev",