feat(client): UI primitives 基线（E2）

- 引入 Radix Dialog/DropdownMenu/Tabs + CVA
- 新增 Button/Input/Dialog/Tabs/Table/Card 等组件（本地拷贝单向同步）
- 增加 touch-target(44px) 样式基础

client/src/components/ui/tabs.tsx

@@ -0,0 +1,51 @@
+import * as React from "react";
+import * as TabsPrimitive from "@radix-ui/react-tabs";
+import { cn } from "../../lib/utils";
+
+export const Tabs = TabsPrimitive.Root;
+
+export const TabsList = React.forwardRef<
+  React.ElementRef<typeof TabsPrimitive.List>,
+  React.ComponentPropsWithoutRef<typeof TabsPrimitive.List>
+>(({ className, ...props }, ref) => (
+  <TabsPrimitive.List
+    ref={ref}
+    className={cn(
+      "inline-flex h-11 items-center justify-center rounded-lg border border-slate-200 bg-white p-1 text-slate-700",
+      className,
+    )}
+    {...props}
+  />
+));
+
+TabsList.displayName = "TabsList";
+
+export const TabsTrigger = React.forwardRef<
+  React.ElementRef<typeof TabsPrimitive.Trigger>,
+  React.ComponentPropsWithoutRef<typeof TabsPrimitive.Trigger>
+>(({ className, ...props }, ref) => (
+  <TabsPrimitive.Trigger
+    ref={ref}
+    className={cn(
+      "inline-flex h-9 items-center justify-center whitespace-nowrap rounded-md px-3 text-sm font-medium transition-all focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary-200 data-[state=active]:bg-primary data-[state=active]:text-white",
+      className,
+    )}
+    {...props}
+  />
+));
+
+TabsTrigger.displayName = "TabsTrigger";
+
+export const TabsContent = React.forwardRef<
+  React.ElementRef<typeof TabsPrimitive.Content>,
+  React.ComponentPropsWithoutRef<typeof TabsPrimitive.Content>
+>(({ className, ...props }, ref) => (
+  <TabsPrimitive.Content
+    ref={ref}
+    className={cn("mt-4 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary-200", className)}
+    {...props}
+  />
+));
+
+TabsContent.displayName = "TabsContent";
+