release(v1.6.0-alpha): smoke-test release for system-update flow

No functional changes from v1.5.0-alpha — this release exists only to
validate the in-app update pipeline end-to-end (manifest check → staged
download → apply → restart → version bump in UI sidebar).

Dropping just the manifest + artifacts; no manual deploy to the fleet.
.116/.228/.253 should notice within 30 min (periodic update-check
interval) and surface the update in the dashboard.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

neode-ui/package.json

@@ -1,7 +1,7 @@
 {
   "name": "neode-ui",
   "private": true,
-  "version": "1.5.0-alpha",
+  "version": "1.6.0-alpha",
   "type": "module",
   "scripts": {
     "start": "./start-dev.sh",