refactor(#783): 组件目录AssetSelector改名为asset-selector (kebab-case)

- components/AssetSelector → components/asset-selector
- test/components/AssetSelector → test/components/asset-selector
- 更新3处import路径
- 组件文件名保持PascalCase (AssetSelector.tsx)

apps/web/src/pages/editing-planner/components/MediaPanel.tsx

@@ -6,7 +6,7 @@ import React, { useState } from "react"
 import type { EditingTemplate } from "@/api/editing-planner"
 import { MODE_LABELS } from "@/api/editing-planner"
 import type { MediaAsset } from "@/api/template-editor"
-import AssetSelector from "@/components/AssetSelector/AssetSelector"
+import AssetSelector from "@/components/asset-selector/AssetSelector"
 
 interface MediaPanelProps {
   templates: EditingTemplate[]

apps/web/src/test/components/asset-selector/AssetSelector.test.tsx

@@ -1,7 +1,7 @@
 import React from "react"
 import { describe, it, expect, vi } from "vitest"
 import { render, screen } from "@testing-library/react"
-import AssetSelector from "@/components/AssetSelector/AssetSelector"
+import AssetSelector from "@/components/asset-selector/AssetSelector"
 import type { MediaAsset } from "@/api/template-editor"
 
 vi.mock("@/components/ui", () => ({
@@ -18,7 +18,7 @@ vi.mock("@/components/ui", () => ({
   Button: ({ children, onClick }: any) => <button onClick={onClick}>{children}</button>,
 }))
 
-vi.mock("@/components/AssetSelector/AssetSelector.css", () => ({}))
+vi.mock("@/components/asset-selector/AssetSelector.css", () => ({}))
 
 const mockAssets: MediaAsset[] = [
   {