优化组件选择交互与视图适配时机

frontend/src/styles.css

@@ -1253,6 +1253,12 @@ textarea {
   cursor: move;
 }
 
+.flow-canvas .react-flow__nodesselection-rect {
+  border: 0;
+  background: transparent;
+  pointer-events: none;
+}
+
 .sim-node {
   position: relative;
   width: 132px;
@@ -1280,9 +1286,30 @@ textarea {
   transform-origin: center;
 }
 
-.sim-node.selected .sim-node-frame {
-  border-color: #1d6fb8;
-  box-shadow: 0 0 0 3px rgba(29, 111, 184, 0.15);
+.sim-node.selected {
+  outline: 1px dashed #111827;
+  outline-offset: 4px;
+}
+
+.flow-canvas .react-flow__node.component-icon-node {
+  pointer-events: none !important;
+}
+
+.flow-canvas .react-flow__node.component-icon-node .sim-node {
+  pointer-events: none;
+}
+
+.flow-canvas .react-flow__node.component-icon-node .node-symbol-envelope,
+.flow-canvas
+  .react-flow__node.component-icon-node
+  .port-handle.port-connection-idle,
+.flow-canvas
+  .react-flow__node.component-icon-node
+  .port-handle.port-connection-origin,
+.flow-canvas
+  .react-flow__node.component-icon-node
+  .port-handle.port-connection-compatible {
+  pointer-events: auto;
 }
 
 .react-flow__node.validation-error .sim-node-frame {
@@ -1306,6 +1333,7 @@ textarea {
 }
 
 .node-symbol {
+  position: relative;
   display: grid;
   width: 112px;
   height: 84px;
@@ -1314,10 +1342,27 @@ textarea {
 }
 
 .node-symbol > .component-symbol {
+  position: relative;
+  z-index: 1;
   width: 100%;
   height: 100%;
 }
 
+.node-symbol-envelope {
+  position: absolute;
+  z-index: 2;
+  box-sizing: border-box;
+}
+
+.sim-node.component-icon-only.selected {
+  outline: none;
+}
+
+.sim-node.component-icon-only.selected .node-symbol-envelope {
+  outline: 1px dashed #111827;
+  outline-offset: 3px;
+}
+
 .sim-node.symbol-presentation-bare .sim-node-frame,
 .sim-node.symbol-presentation-bare.selected .sim-node-frame,
 .sim-node.component-icon-only .sim-node-frame,
@@ -1334,11 +1379,6 @@ textarea {
   background: transparent;
 }
 
-.sim-node.symbol-presentation-bare.selected .component-symbol-svg,
-.sim-node.component-icon-only.selected .component-symbol-svg {
-  filter: drop-shadow(0 0 3px rgba(29, 111, 184, 0.62));
-}
-
 .react-flow__node.validation-error
   .sim-node.component-icon-only
   .component-symbol-svg {