style(web): refine subagent navigation chrome

packages/client/ui-subagent/src/client/SubagentCatalogAction.module.css

@@ -41,7 +41,7 @@
   width: 336px;
   max-width: min(400px, calc(100vw - 32px));
   max-height: min(560px, calc(100vh - 140px));
-  padding: 6px;
+  padding: 4px;
   overflow: auto;
   border: 1px solid var(--dsw-alias-border-l2);
   border-radius: 12px;
@@ -64,7 +64,7 @@
   box-sizing: border-box;
   width: 100%;
   min-height: 50px;
-  padding: 7px 8px;
+  padding: 7px 8px 7px 3px;
   border: 0;
   border-radius: 8px;
   background: transparent;
@@ -154,17 +154,40 @@
 
 .children {
   position: relative;
-  margin-left: 15px;
-  padding-left: 11px;
+  margin-left: 10px;
+  padding-left: 4px;
+}
+
+.children::before,
+.children > .node::before {
+  content: '';
+  position: absolute;
+  left: 0;
   border-left: 1px solid var(--dsw-alias-border-l2);
 }
 
+.children::before {
+  top: -26px;
+  height: 26px;
+}
+
+.children > .node::before {
+  top: 0;
+  bottom: 0;
+  left: -4px;
+}
+
+.children > .node:last-child::before {
+  bottom: auto;
+  height: 25px;
+}
+
 .children > .node > .row::before {
   content: '';
   position: absolute;
   top: 24px;
-  left: -12px;
-  width: 9px;
+  left: -4px;
+  width: 7px;
   border-top: 1px solid var(--dsw-alias-border-l2);
 }