chore(frontend): shadcn-svelte / Tailwind / layerchart 工具链初始化

[变更性质]
本轮为维护性依赖与配置初始化，不改变业务页面（页面迁移见后续提交）。

[维护内容]
按 Leader 返工指令，前端 UI 组件库全量迁移 shadcn-svelte，图表渲染
从 echarts 换为 layerchart，需要一次性引入配套依赖与构建配置。

[实现方案]
package.json/pnpm-lock.yaml：tailwindcss@4、@tailwindcss/vite、
tw-animate-css、shadcn-svelte、bits-ui、tailwind-variants、clsx、
tailwind-merge、@lucide/svelte、layerchart、@fontsource-variable/inter
与 @types/node；echarts 保留至页面迁移完成后移除。pnpm-workspace.yaml
声明 allowBuilds（esbuild、@tailwindcss/oxide）。components.json 采用
mira preset，别名 $lib。tsconfig 新增 $lib paths；vite.config.ts 加入
tailwindcss 插件、$lib alias（vitest 需要）与 test 环境配置。
src/lib/components/ 为 shadcn 生成的 UI 组件源码（button/input/label/
card/badge/alert/select/table/tabs/separator/chart），src/lib/utils.ts
为 cn 工具。app.css 引入 tailwind 与 shadcn CSS 变量并调整为 teal
主题（primary #0f766e、radius 0.375rem、双主题 chart-1..5），保留
legacy 选择器（banner/beat/table.data/metric 等），mobileCss.test.ts
依赖其语义断言。

[影响范围]
构建链与主题变量；后续页面提交逐步消费这些组件，npm run check/test/
build 已全绿验证。

5 files changed, 117 insertions, 0 deletions

diff --git a/frontend/src/lib/components/ui/tabs/index.ts b/frontend/src/lib/components/ui/tabs/index.ts
new file mode 100644
index 0000000..581b188
--- /dev/null
+++ b/frontend/src/lib/components/ui/tabs/index.ts
@@ -0,0 +1,18 @@
+import Content from "./tabs-content.svelte";
+import Trigger from "./tabs-trigger.svelte";
+import Root from "./tabs.svelte";
+import List, { tabsListVariants, type TabsListVariant } from "./tabs-list.svelte";
+
+export {
+	Root,
+	Content,
+	List,
+	Trigger,
+	tabsListVariants,
+	type TabsListVariant,
+	//
+	Root as Tabs,
+	Content as TabsContent,
+	List as TabsList,
+	Trigger as TabsTrigger,
+};
diff --git a/frontend/src/lib/components/ui/tabs/tabs-content.svelte b/frontend/src/lib/components/ui/tabs/tabs-content.svelte
new file mode 100644
index 0000000..b9e4530
--- /dev/null
+++ b/frontend/src/lib/components/ui/tabs/tabs-content.svelte
@@ -0,0 +1,17 @@
+<script lang="ts">
+	import { Tabs as TabsPrimitive } from "bits-ui";
+	import { cn } from "$lib/utils.js";
+
+	let {
+		ref = $bindable(null),
+		class: className,
+		...restProps
+	}: TabsPrimitive.ContentProps = $props();
+</script>
+
+<TabsPrimitive.Content
+	bind:ref
+	data-slot="tabs-content"
+	class={cn("text-xs/relaxed flex-1 outline-none", className)}
+	{...restProps}
+/>
diff --git a/frontend/src/lib/components/ui/tabs/tabs-list.svelte b/frontend/src/lib/components/ui/tabs/tabs-list.svelte
new file mode 100644
index 0000000..4445c0f
--- /dev/null
+++ b/frontend/src/lib/components/ui/tabs/tabs-list.svelte
@@ -0,0 +1,40 @@
+<script lang="ts" module>
+	import { tv, type VariantProps } from "tailwind-variants";
+
+	export const tabsListVariants = tv({
+		base: "rounded-lg p-[3px] group-data-horizontal/tabs:h-8 data-[variant=line]:rounded-none group/tabs-list inline-flex w-fit items-center justify-center text-muted-foreground group-data-vertical/tabs:h-fit group-data-vertical/tabs:flex-col",
+		variants: {
+			variant: {
+				default: "bg-muted",
+				line: "gap-1 bg-transparent",
+			},
+		},
+		defaultVariants: {
+			variant: "default",
+		},
+	});
+
+	export type TabsListVariant = VariantProps<typeof tabsListVariants>["variant"];
+</script>
+
+<script lang="ts">
+	import { Tabs as TabsPrimitive } from "bits-ui";
+	import { cn } from "$lib/utils.js";
+
+	let {
+		ref = $bindable(null),
+		variant = "default",
+		class: className,
+		...restProps
+	}: TabsPrimitive.ListProps & {
+		variant?: TabsListVariant;
+	} = $props();
+</script>
+
+<TabsPrimitive.List
+	bind:ref
+	data-slot="tabs-list"
+	data-variant={variant}
+	class={cn(tabsListVariants({ variant }), className)}
+	{...restProps}
+/>
diff --git a/frontend/src/lib/components/ui/tabs/tabs-trigger.svelte b/frontend/src/lib/components/ui/tabs/tabs-trigger.svelte
new file mode 100644
index 0000000..c243f83
--- /dev/null
+++ b/frontend/src/lib/components/ui/tabs/tabs-trigger.svelte
@@ -0,0 +1,23 @@
+<script lang="ts">
+	import { Tabs as TabsPrimitive } from "bits-ui";
+	import { cn } from "$lib/utils.js";
+
+	let {
+		ref = $bindable(null),
+		class: className,
+		...restProps
+	}: TabsPrimitive.TriggerProps = $props();
+</script>
+
+<TabsPrimitive.Trigger
+	bind:ref
+	data-slot="tabs-trigger"
+	class={cn(
+		"gap-1.5 rounded-md border border-transparent px-1.5 py-0.5 text-xs font-medium group-data-vertical/tabs:py-[calc(--spacing(1.25))] [&_svg:not([class*='size-'])]:size-3.5 has-data-[icon=inline-end]:pr-1 has-data-[icon=inline-start]:pl-1 relative inline-flex h-[calc(100%_-_1px)] flex-1 items-center justify-center whitespace-nowrap text-foreground/60 transition-all group-data-vertical/tabs:w-full group-data-vertical/tabs:justify-start hover:text-foreground focus-visible:border-ring focus-visible:ring-[3px] focus-visible:ring-ring/50 focus-visible:outline-1 focus-visible:outline-ring disabled:pointer-events-none disabled:opacity-50 dark:text-muted-foreground dark:hover:text-foreground [&_svg]:pointer-events-none [&_svg]:shrink-0",
+		"group-data-[variant=line]/tabs-list:bg-transparent group-data-[variant=line]/tabs-list:data-active:bg-transparent dark:group-data-[variant=line]/tabs-list:data-active:border-transparent dark:group-data-[variant=line]/tabs-list:data-active:bg-transparent",
+		"data-active:bg-background data-active:text-foreground dark:data-active:border-input dark:data-active:bg-input/30 dark:data-active:text-foreground",
+		"after:absolute after:bg-foreground after:opacity-0 after:transition-opacity group-data-horizontal/tabs:after:inset-x-0 group-data-horizontal/tabs:after:bottom-[-5px] group-data-horizontal/tabs:after:h-0.5 group-data-vertical/tabs:after:inset-y-0 group-data-vertical/tabs:after:-right-1 group-data-vertical/tabs:after:w-0.5 group-data-[variant=line]/tabs-list:data-active:after:opacity-100",
+		className
+	)}
+	{...restProps}
+/>
diff --git a/frontend/src/lib/components/ui/tabs/tabs.svelte b/frontend/src/lib/components/ui/tabs/tabs.svelte
new file mode 100644
index 0000000..a7b461a
--- /dev/null
+++ b/frontend/src/lib/components/ui/tabs/tabs.svelte
@@ -0,0 +1,19 @@
+<script lang="ts">
+	import { Tabs as TabsPrimitive } from "bits-ui";
+	import { cn } from "$lib/utils.js";
+
+	let {
+		ref = $bindable(null),
+		value = $bindable(""),
+		class: className,
+		...restProps
+	}: TabsPrimitive.RootProps = $props();
+</script>
+
+<TabsPrimitive.Root
+	bind:ref
+	bind:value
+	data-slot="tabs"
+	class={cn("gap-2 group/tabs flex data-horizontal:flex-col", className)}
+	{...restProps}
+/>