refactor(ui): restrict external asset overrides to development mode

assets/icons/pdf.svg

@@ -1,13 +1,7 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48" width="48" height="48">
-  <!-- Folha de documento com dobra -->
-  <path d="M 8 4 L 32 4 L 42 14 L 42 44 L 8 44 Z" fill="#ffffff" stroke="#d32f2f" stroke-width="2.5" stroke-linejoin="round"/>
-  <!-- Dobra de canto -->
-  <path d="M 32 4 L 32 14 L 42 14 Z" fill="#ffcdd2" stroke="#d32f2f" stroke-width="2" stroke-linejoin="round"/>
-  <!-- Linhas de texto representativas -->
-  <line x1="13" y1="18" x2="27" y2="18" stroke="#b0bec5" stroke-width="2" stroke-linecap="round"/>
-  <line x1="13" y1="22" x2="35" y2="22" stroke="#b0bec5" stroke-width="2" stroke-linecap="round"/>
-  <line x1="13" y1="26" x2="35" y2="26" stroke="#b0bec5" stroke-width="2" stroke-linecap="round"/>
-  <!-- Etiqueta vermelha com sigla PDF perfeitamente centralizada -->
-  <rect x="11" y="31" width="28" height="11" rx="3" fill="#d32f2f"/>
-  <text x="25" y="36.5" font-family="'Segoe UI', Arial, sans-serif" font-size="8.5px" font-weight="bold" fill="#ffffff" text-anchor="middle" dominant-baseline="central">PDF</text>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24">
+  <path d="M 5 3.5 H 14 L 19 8.5 V 20.5 C 19 21.1 18.5 21.5 17.9 21.5 H 5 C 4.4 21.5 4 21.1 4 20.5 V 4.5 C 4 3.9 4.4 3.5 5 3.5 Z" 
+        fill="none" stroke="currentColor" stroke-width="2" stroke-linejoin="round"/>
+  <path d="M 14 3.5 V 8.5 H 19" fill="none" stroke="currentColor" stroke-width="2" stroke-linejoin="round"/>
+  <rect x="7" y="12" width="10" height="6" rx="1.5" fill="#ef4444"/>
+  <path d="M 9 14 H 10.5 C 11 14 11.5 14.3 11.5 14.8 C 11.5 15.3 11 15.6 10.5 15.6 H 9 V 17 M 9 15.6 H 10.5" stroke="#ffffff" stroke-width="1" stroke-linecap="round" fill="none"/>
 </svg>