refactor(ui): remove icon from OpenClaw config cards

- Hide card icon (first letter circle) from config cards
- Remove left visual anchor for cleaner look

Author: ymkiux

web-ui/styles/openclaw-structured.css

@@ -484,6 +484,10 @@
     gap: 10px;
 }
 
+.openclaw-card-list .card-icon {
+    display: none;
+}
+
 .openclaw-card-list .card-leading {
     width: 100%;
 }