feat(ui): Kammergut gloss test on the logo badge inner circle

Black gloss paint from plan-b's Kammergut wordmark (verbatim #paintGloss
SVG filter + the .paint-3d sheen gradient) applied to
.logo-gradient-border::after — the circle behind the A on the
screensaver, intro, splash and login. Marked as a TEST in both files;
revert = git revert of this one commit.

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

neode-ui/src/App.vue

@@ -1,5 +1,39 @@
 <template>
   <div id="app">
+    <!-- KAMMERGUT GLOSS TEST (2026-08-12): SVG paint filter lifted verbatim
+         from plan-b's Kammergut wordmark (#paintGloss). Consumed by the
+         .logo-gradient-border::after override in style.css. Revert by
+         deleting this svg block + that css block (one commit). -->
+    <svg width="0" height="0" style="position:absolute" aria-hidden="true" focusable="false">
+      <defs>
+        <filter id="paintGloss" x="-12%" y="-30%" width="124%" height="160%" color-interpolation-filters="sRGB">
+          <feMorphology in="SourceAlpha" operator="dilate" radius="2.5" result="dilated"/>
+          <feGaussianBlur in="dilated" stdDeviation="6" result="puddle"/>
+          <feFlood flood-color="#fff4dc" flood-opacity="0.85" result="puddleColor"/>
+          <feComposite in="puddleColor" in2="puddle" operator="in" result="puddleHi"/>
+          <feFlood flood-color="#1A1A18" flood-opacity="0.18" result="puddleShadowColor"/>
+          <feComposite in="puddleShadowColor" in2="puddle" operator="in" result="puddleShadow"/>
+          <feOffset in="puddleShadow" dx="0" dy="3" result="puddleShadowOff"/>
+          <feGaussianBlur in="SourceAlpha" stdDeviation="1.4" result="bump"/>
+          <feSpecularLighting in="bump" surfaceScale="4" specularConstant="0.9"
+                              specularExponent="40" lighting-color="#fff2d4" result="spec2">
+            <fePointLight x="600" y="-200" z="380"/>
+          </feSpecularLighting>
+          <feComposite in="spec2" in2="SourceAlpha" operator="in" result="specClip2"/>
+          <feGaussianBlur in="SourceAlpha" stdDeviation="4" result="dsBlur"/>
+          <feOffset in="dsBlur" dx="0" dy="6" result="dsOff"/>
+          <feComponentTransfer in="dsOff" result="dsFinal">
+            <feFuncA type="linear" slope="0.45"/>
+          </feComponentTransfer>
+          <feMerge>
+            <feMergeNode in="dsFinal"/>
+            <feMergeNode in="SourceGraphic"/>
+            <feMergeNode in="specClip2"/>
+          </feMerge>
+        </filter>
+      </defs>
+    </svg>
+
     <!-- Splash Screen (only on first visit) -->
     <SplashScreen v-if="showSplash" @complete="handleSplashComplete" />
 

neode-ui/src/style.css

@@ -1128,6 +1128,16 @@ html.controller-nav [data-controller-container]:focus {
     z-index: 0;
   }
 
+  /* KAMMERGUT GLOSS TEST (2026-08-12) — black gloss paint on the badge's
+     inner circle, lifted from plan-b's Kammergut wordmark (.paint-3d
+     gradient + #paintGloss filter, defs injected in App.vue). Revert:
+     delete this block + the svg defs block in App.vue (one commit). */
+  .logo-gradient-border::after {
+    background: linear-gradient(180deg, #2a2a26 0%, #1a1a18 45%, #060604 100%);
+    filter: url(#paintGloss);
+    -webkit-filter: url(#paintGloss);
+  }
+
   .logo-gradient-border img,
   .logo-gradient-border svg {
     border-radius: 9999px;