feat: 新增引导式新手指引 (OnboardingTour) 组件，全站页面接入

src/features/assets/AssetsPage.tsx

@@ -10,7 +10,7 @@ import {
   SearchOutlined,
   UserOutlined,
 } from "@ant-design/icons";
-import { useCallback, useEffect, useMemo, useRef, useState, type JSX } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState, type ChangeEvent, type DragEvent, type JSX } from "react";
 import "../../styles/pages/assets.css";
 import { assetClient, type ServerAssetItem } from "../../api/assetClient";
 import { aiGenerationClient } from "../../api/aiGenerationClient";
@@ -95,6 +95,17 @@ function AssetsPage({ isAuthenticated, onOpenLogin }: AssetsPageProps) {
   const [contextMenu, setContextMenu] = useState<{ x: number; y: number; asset: LibraryAssetItem } | null>(null);
   const contextMenuRef = useRef<HTMLDivElement>(null);
   const uploadInputRef = useRef<HTMLInputElement>(null);
+  const [isUploadDragging, setIsUploadDragging] = useState(false);
+
+  const handleUploadDragOver = (e: DragEvent) => { e.preventDefault(); if (e.dataTransfer.types.includes("Files")) setIsUploadDragging(true); };
+  const handleUploadDragLeave = (e: DragEvent) => { e.preventDefault(); if (!e.currentTarget.contains(e.relatedTarget as Node)) setIsUploadDragging(false); };
+  const handleUploadDrop = (e: DragEvent) => {
+    e.preventDefault();
+    setIsUploadDragging(false);
+    if (e.dataTransfer.files.length) {
+      void handleUploadFiles(e.dataTransfer.files);
+    }
+  };
 
   const handleContextMenu = useCallback((e: React.MouseEvent, asset: LibraryAssetItem) => {
     e.preventDefault();
@@ -270,7 +281,15 @@ function AssetsPage({ isAuthenticated, onOpenLogin }: AssetsPageProps) {
               placeholder="搜索资产..."
             />
           </label>
-          <button type="button" className="studio-generate-btn studio-generate-btn--compact" onClick={() => uploadInputRef.current?.click()} disabled={isUploading}>
+          <button
+            type="button"
+            className={`studio-generate-btn studio-generate-btn--compact${isUploadDragging ? " is-dragging" : ""}`}
+            onClick={() => uploadInputRef.current?.click()}
+            onDragOver={handleUploadDragOver}
+            onDragLeave={handleUploadDragLeave}
+            onDrop={handleUploadDrop}
+            disabled={isUploading}
+          >
             {isUploading ? <LoadingOutlined /> : <PlusOutlined />}
             {isUploading ? "上传中..." : "添加"}
           </button>