style(icons): apply reviewed icon set

assets/icons/blocks/block.svg

@@ -1,14 +1,6 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24">
-  <!-- Small objects being grouped -->
-  <circle cx="8.5" cy="8.5" r="2" fill="none" stroke="#cccccc" stroke-width="1.3"/>
-  <line x1="13" y1="7" x2="17" y2="10" stroke="#cccccc" stroke-width="1.3" stroke-linecap="round"/>
-  <rect x="12.5" y="12" width="4" height="3" fill="none" stroke="#cccccc" stroke-width="1.2" rx="0.5"/>
-  <!-- Dashed selection boundary -->
-  <rect x="4.5" y="4.5" width="15" height="15" fill="none" stroke="#aaaaaa" stroke-width="1.2"
-        stroke-dasharray="2.5,1.5" rx="1"/>
-  <!-- Base point indicator at bottom-left corner -->
-  <circle cx="4.5" cy="19.5" r="1.5" fill="#4a9eff"/>
-  <!-- Small cross at base point -->
-  <line x1="2.5" y1="19.5" x2="6.5" y2="19.5" stroke="#4a9eff" stroke-width="1" stroke-linecap="round"/>
-  <line x1="4.5" y1="17.5" x2="4.5" y2="21.5" stroke="#4a9eff" stroke-width="1" stroke-linecap="round"/>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" role="img" aria-label="Block">
+  <rect x="3" y="3" width="18" height="18" stroke-dasharray="None" rx="1.5" stroke="#B4B6B9" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <rect x="6" y="7" width="5" height="4" rx="0.6" stroke="#B4B6B9" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <circle cx="16" cy="15" r="3" stroke="#B4B6B9" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <circle cx="4" cy="4" r="1.3" stroke="none" fill="#6DB7ED"/>
 </svg>

assets/icons/blocks/insert.svg

@@ -1,17 +1,8 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24">
-  <!-- Block reference boundary -->
-  <rect x="6" y="5" width="12" height="10" fill="none" stroke="#cccccc" stroke-width="1.4" rx="1"/>
-  <!-- Block interior cross (represents block content) -->
-  <line x1="9" y1="10" x2="15" y2="10" stroke="#888888" stroke-width="1"/>
-  <line x1="12" y1="7" x2="12" y2="13" stroke="#888888" stroke-width="1"/>
-  <!-- Corner handle marks -->
-  <rect x="5" y="4" width="2" height="2" fill="#aaaaaa" rx="0.3"/>
-  <rect x="17" y="4" width="2" height="2" fill="#aaaaaa" rx="0.3"/>
-  <rect x="5" y="14" width="2" height="2" fill="#aaaaaa" rx="0.3"/>
-  <rect x="17" y="14" width="2" height="2" fill="#aaaaaa" rx="0.3"/>
-  <!-- Insertion arrow pointing down to base point -->
-  <line x1="12" y1="16" x2="12" y2="20.5" stroke="#4a9eff" stroke-width="1.5" stroke-linecap="round"/>
-  <polyline points="9.5,18.5 12,21 14.5,18.5"
-            fill="none" stroke="#4a9eff" stroke-width="1.5"
-            stroke-linecap="round" stroke-linejoin="round"/>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" role="img" aria-label="Insert">
+  <rect x="3" y="3" width="18" height="18" stroke-dasharray="None" rx="1.5" stroke="#B4B6B9" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <rect x="6" y="7" width="5" height="4" rx="0.6" stroke="#B4B6B9" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <circle cx="16" cy="15" r="3" stroke="#B4B6B9" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <line x1="3" y1="18" x2="9" y2="18" stroke="#6DB7ED" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <line x1="9" y1="18" x2="7.09087686895899" y2="19.28267255000026" stroke="#6DB7ED" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+  <line x1="9" y1="18" x2="7.09087686895899" y2="16.71732744999974" stroke="#6DB7ED" stroke-width="1.625" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
 </svg>