tweak(ui): use new-session icon in sidebar buttons

packages/app/src/pages/layout.tsx

@@ -2066,7 +2066,7 @@ export default function Layout(props: ParentProps) {
                       <div class="shrink-0 py-4">
                         <Button
                           size="large"
-                          icon="plus-small"
+                          icon="new-session"
                           class="w-full"
                           onClick={() => navigateWithSidebarReset(`/${base64Encode(p().worktree)}/session`)}
                         >

packages/app/src/pages/layout/sidebar-items.tsx

@@ -384,7 +384,7 @@ export const NewSessionItem = (props: {
     >
       <div class="flex items-center gap-1 w-full">
         <div class="shrink-0 size-6 flex items-center justify-center">
-          <Icon name="plus-small" size="small" class="text-icon-weak" />
+          <Icon name="new-session" size="small" class="text-icon-weak" />
         </div>
         <span class="text-14-regular text-text-strong grow-1 min-w-0 overflow-hidden text-ellipsis truncate">
           {label}

packages/app/src/pages/layout/sidebar-workspace.tsx

@@ -217,7 +217,7 @@ const WorkspaceActions = (props: {
     <Show when={!props.touch()}>
       <Tooltip value={props.language.t("command.session.new")} placement="top">
         <IconButton
-          icon="plus-small"
+          icon="new-session"
           variant="ghost"
           class="size-6 rounded-md opacity-0 pointer-events-none group-hover/workspace:opacity-100 group-hover/workspace:pointer-events-auto group-focus-within/workspace:opacity-100 group-focus-within/workspace:pointer-events-auto"
           data-action="workspace-new-session"

packages/ui/src/components/button.css

@@ -115,7 +115,7 @@
 
     font-size: var(--font-size-small);
     line-height: var(--line-height-large);
-    gap: 4px;
+    gap: 8px;
 
     /* text-12-medium */
     font-family: var(--font-family-sans);
@@ -135,7 +135,7 @@
     }
 
     font-size: var(--font-size-small);
-    gap: 6px;
+    gap: 8px;
 
     /* text-12-medium */
     font-family: var(--font-family-sans);
@@ -153,7 +153,7 @@
       padding: 0 12px 0 8px;
     }
 
-    gap: 4px;
+    gap: 8px;
 
     /* text-14-medium */
     font-family: var(--font-family-sans);