feat(ui): app icons on the house canvas; detail page gets the tile treatment

- alby-hub + phoenixd icons re-set with the standard 12% inner margin
  (they shipped edge-to-edge; every other icon carries whitespace).
- scripts/normalize-app-icon.py: wraps any third-party SVG mark onto the
  house canvas — the system applies the tile plate (archy-app-icon)
  automatically but deliberately no runtime inset, so the margin must be
  baked; the guide now says exactly that.
- MarketplaceAppDetails: the icon now carries archy-app-icon like the
  store tiles — the treatment no longer stops at the detail page.
- v1.8.2 changelog: third curated bullet (the ceremony gate requires 3).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/src/views/MarketplaceAppDetails.vue

@@ -23,7 +23,7 @@
             v-if="app.icon"
             :src="app.icon"
             :alt="app.title"
-            class="w-20 h-20 rounded-xl shadow-xl flex-shrink-0"
+            class="w-20 h-20 rounded-xl shadow-xl flex-shrink-0 archy-app-icon"
             @error="handleImageError"
           />
           <div v-else class="w-20 h-20 rounded-xl bg-white/10 flex items-center justify-center flex-shrink-0">
@@ -99,7 +99,7 @@
               v-if="app.icon"
               :src="app.icon"
               :alt="app.title"
-              class="w-20 h-20 rounded-xl shadow-xl"
+              class="w-20 h-20 rounded-xl shadow-xl archy-app-icon"
               @error="handleImageError"
             />
             <div v-else class="w-20 h-20 rounded-xl bg-white/10 flex items-center justify-center">