frontend: build three-pane workspace shell with collapsible panels and synced path state

Co-authored-by: Cursor <cursoragent@cursor.com>

mactfsui/app/components/inspector/changes-panel.tsx

@@ -0,0 +1,22 @@
+import { ListChecks } from "lucide-react"
+
+/**
+ * 右侧 Changes 面板骨架：Pending Changes 列表与 Checkin 入口在 FE-010 实现。
+ */
+export function ChangesPanel() {
+  return (
+    <aside className="flex h-full w-[340px] shrink-0 flex-col border-l bg-sidebar">
+      <div className="flex h-9 shrink-0 items-center border-b px-3">
+        <span className="text-xs font-medium text-muted-foreground">挂起更改</span>
+      </div>
+      <div className="flex flex-1 items-center justify-center p-4">
+        <div className="flex flex-col items-center gap-2 text-center">
+          <ListChecks className="size-6 text-muted-foreground/60" />
+          <p className="text-xs leading-5 text-muted-foreground">
+            挂起更改与签入将在后续任务实现
+          </p>
+        </div>
+      </div>
+    </aside>
+  )
+}