feat(icons): replace 16px logo with bare medallion variant

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

extension/icons/relicario-logo-16.svg

@@ -1,24 +1,30 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" fill="none">
-  <!-- 16x16-optimized: bolder strokes, simplified details, single gem
-       facet for crisp pixels at toolbar size. -->
+  <defs>
+    <radialGradient id="redThecaSm" cx="0.4" cy="0.35">
+      <stop offset="0%" stop-color="#9a1a1a"/>
+      <stop offset="100%" stop-color="#3a0a0a"/>
+    </radialGradient>
+    <linearGradient id="goldRingSm" x1="0" x2="1">
+      <stop offset="0%" stop-color="#d2ab43"/>
+      <stop offset="50%" stop-color="#f5d97a"/>
+      <stop offset="100%" stop-color="#7c5719"/>
+    </linearGradient>
+  </defs>
 
-  <!-- Base plate -->
-  <rect x="1" y="13" width="14" height="2" rx="0.5" fill="#58a6ff"/>
+  <!-- Body + theca -->
+  <circle cx="8" cy="9" r="6.5" fill="url(#goldRingSm)"/>
+  <circle cx="8" cy="9" r="4.8" fill="url(#redThecaSm)"/>
 
-  <!-- Arched reliquary body -->
-  <path d="M 3 13
-           L 3 6
-           C 3 3.5, 5 2, 8 2
-           C 11 2, 13 3.5, 13 6
-           L 13 13 Z"
-        fill="#161b22"
-        stroke="#58a6ff"
-        stroke-width="1"
-        stroke-linejoin="round"/>
+  <!-- Asterisk-as-3-bars -->
+  <g transform="translate(8, 9)" stroke="#f5d97a" stroke-width="1.2" stroke-linecap="round">
+    <line x1="0" y1="-3" x2="0" y2="3"/>
+    <line x1="-2.6" y1="-1.5" x2="2.6" y2="1.5"/>
+    <line x1="-2.6" y1="1.5" x2="2.6" y2="-1.5"/>
+  </g>
+  <circle cx="8" cy="9" r="0.7" fill="#fff3cf"/>
 
-  <!-- Seal band -->
-  <rect x="3" y="6" width="10" height="1" fill="#58a6ff"/>
-
-  <!-- Central gem — a simple filled diamond -->
-  <path d="M 8 8 L 10 10 L 8 12 L 6 10 Z" fill="#58a6ff"/>
+  <!-- Fleur (3 tips) -->
+  <path d="M 8 0 L 7.2 2.5 L 8.8 2.5 Z" fill="url(#goldRingSm)"/>
+  <path d="M 5.6 2.5 L 6.5 1 L 7.3 2.5 Z" fill="url(#goldRingSm)"/>
+  <path d="M 10.4 2.5 L 9.5 1 L 8.7 2.5 Z" fill="url(#goldRingSm)"/>
 </svg>