style(ui-control): remove focus ring, make focus/open states match hover

- Remove box-shadow focus ring that looked jarring
- Use same background and border color for hover/focus/open states
- More consistent visual feedback without glowing effect

web/src/index.css

@@ -253,8 +253,8 @@ pre,
 .ui-control:focus,
 .ui-control:focus-visible {
   background: var(--bg-tertiary);
-  border-color: var(--bg-accent);
-  box-shadow: 0 0 0 3px var(--focus-ring);
+  border-color: var(--border-hover);
+  outline: none;
 }
 
 .ui-control:disabled {
@@ -263,7 +263,7 @@ pre,
 }
 
 .ui-control-open {
-  border-color: var(--bg-accent) !important;
+  border-color: var(--border-hover) !important;
   background: var(--bg-tertiary);
 }