fix: make browser Go button icon-only

Remove the visible Go label and use the toolbar icon-button width while preserving the tooltip and accessible name.

src/renderer/src/RightAssistantSidebar.tsx

@@ -639,7 +639,6 @@ function BrowserToolbar({
         type="submit"
       >
         <ArrowRight aria-hidden="true" size={13} />
-        <span>{t('sidebar.browser.toolbar.go')}</span>
       </button>
       <button
         aria-label={

src/renderer/src/styles.css

@@ -5281,7 +5281,8 @@ button > svg {
   gap: var(--space-1);
 }
 
-.assistant-sidebar__browser-tool-button {
+.assistant-sidebar__browser-tool-button,
+.assistant-sidebar__browser-go {
   width: var(--control-height);
   padding: 0;
   flex: 0 0 var(--control-height);
@@ -5312,14 +5313,6 @@ button > svg {
     flex-basis: calc(100% - var(--control-height) - var(--space-1));
   }
 
-  .assistant-sidebar__browser-go {
-    width: var(--control-height);
-    padding: 0;
-  }
-
-  .assistant-sidebar__browser-go > span {
-    display: none;
-  }
 }
 
 .assistant-sidebar__browser-address input {
@@ -5339,11 +5332,6 @@ button > svg {
   border-color: var(--accent);
 }
 
-.assistant-sidebar__browser-go {
-  padding: 0 var(--space-2);
-  flex: 0 0 auto;
-}
-
 .assistant-sidebar__browser-tool-button:hover:not(:disabled),
 .assistant-sidebar__browser-go:hover:not(:disabled) {
   border-color: var(--accent-selected);