release(v1.7.18-alpha): transitive peers default Trusted + update-flow logs

Flip transitively-discovered federation peers to Trusted instead of
Observer. Hints are already only ingested from peers we trust and only
peers we trust are re-exported via build_local_state, so the chain of
trust is already vetted end-to-end — making the user promote each
newcomer by hand was friction with no security win.

Backend:
- federation/sync.rs: merge_transitive_peers now inserts TrustLevel::Trusted
  (doc comment updated to explain the transitive-trust rationale)
- update.rs: info! log at download start (version, components, total_bytes,
  staging path), cancel (staging wiped?, marker cleared?), and apply (backup
  path) so journalctl reveals where a stuck update actually is

Frontend:
- SystemUpdate What's New block gets a v1.7.18-alpha entry

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

neode-ui/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "neode-ui",
-  "version": "1.3.5",
+  "version": "1.6.0-alpha",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "neode-ui",
-      "version": "1.3.5",
+      "version": "1.6.0-alpha",
       "dependencies": {
         "@types/dompurify": "^3.0.5",
         "@vue-leaflet/vue-leaflet": "^0.10.1",

neode-ui/src/views/settings/AccountInfoSection.vue

@@ -180,6 +180,17 @@ init()
               </button>
             </div>
             <div class="overflow-y-auto flex-1 min-h-0 space-y-6 pr-1">
+              <!-- v1.7.18-alpha -->
+              <div>
+                <div class="flex items-center gap-2 mb-3">
+                  <span class="text-xs font-mono px-2 py-0.5 rounded bg-orange-500/20 text-orange-300">v1.7.18-alpha</span>
+                  <span class="text-xs text-white/40">Apr 20, 2026</span>
+                </div>
+                <div class="space-y-3 text-sm text-white/80 pl-3 border-l border-white/10">
+                  <p>Nodes discovered through a trusted peer now land as Trusted instead of Observer. When your federated peer shares its own peer list with you, those nodes get the same trust level as a direct invite — the link they came through is already one you vetted, so you no longer need to promote them by hand before they can be used normally.</p>
+                  <p>The update flow now writes clearer logs at every step. Start of download, cancel, and apply each emit a one-line entry to the system journal with the staging path and the affected files, so if a download misbehaves on your node it's easy to see exactly where it got to.</p>
+                </div>
+              </div>
               <!-- v1.7.17-alpha -->
               <div>
                 <div class="flex items-center gap-2 mb-3">