feat(huggingface): implement direct upload for large files (>20MB)

- Add frontend direct upload to HuggingFace S3, bypassing CF Workers limits
- Add /api/huggingface/getUploadUrl endpoint to get LFS upload URLs
- Add /api/huggingface/commitUpload endpoint to commit file references
- Support multipart upload for very large files
- SHA256 computed in frontend to avoid CF Workers CPU timeout
- Small files (<20MB) still use proxy upload through CF Workers

functions/api/huggingface/getUploadUrl.js

@@ -0,0 +1,105 @@
+/**
+ * HuggingFace 大文件直传 API
+ * 
+ * 流程：
+ * 1. 前端计算 SHA256 和文件样本
+ * 2. 前端调用此 API 获取 LFS 上传 URL
+ * 3. 前端直接上传到 HuggingFace S3
+ * 4. 前端调用 commitUpload API 提交文件引用
+ * 
+ * 这样可以绕过 CF Workers 的 100MB 请求体限制和 CPU 时间限制
+ */
+
+import { HuggingFaceAPI } from '../../utils/huggingfaceAPI.js';
+import { getUploadConfig } from '../../utils/sysConfig.js';
+
+export async function onRequestPost(context) {
+    const { request, env } = context;
+
+    try {
+        // 验证认证码
+        const authCode = request.headers.get('authcode');
+        if (env.AUTH_CODE && authCode !== env.AUTH_CODE) {
+            return new Response(JSON.stringify({ error: 'Unauthorized' }), {
+                status: 401,
+                headers: { 'Content-Type': 'application/json' }
+            });
+        }
+
+        const body = await request.json();
+        const { fileSize, fileName, sha256, fileSample, channelName } = body;
+
+        if (!fileSize || !fileName || !sha256 || !fileSample) {
+            return new Response(JSON.stringify({ 
+                error: 'Missing required fields: fileSize, fileName, sha256, fileSample' 
+            }), {
+                status: 400,
+                headers: { 'Content-Type': 'application/json' }
+            });
+        }
+
+        // 获取 HuggingFace 配置
+        const uploadConfig = await getUploadConfig(env);
+        const hfSettings = uploadConfig.huggingface;
+
+        if (!hfSettings || !hfSettings.channels || hfSettings.channels.length === 0) {
+            return new Response(JSON.stringify({ error: 'No HuggingFace channel configured' }), {
+                status: 400,
+                headers: { 'Content-Type': 'application/json' }
+            });
+        }
+
+        // 选择渠道
+        let hfChannel;
+        if (channelName) {
+            hfChannel = hfSettings.channels.find(c => c.name === channelName);
+        }
+        if (!hfChannel) {
+            hfChannel = hfSettings.loadBalance?.enabled
+                ? hfSettings.channels[Math.floor(Math.random() * hfSettings.channels.length)]
+                : hfSettings.channels[0];
+        }
+
+        if (!hfChannel || !hfChannel.token || !hfChannel.repo) {
+            return new Response(JSON.stringify({ error: 'HuggingFace channel not properly configured' }), {
+                status: 400,
+                headers: { 'Content-Type': 'application/json' }
+            });
+        }
+
+        // 构建文件路径
+        const now = new Date();
+        const yearMonth = `${now.getFullYear()}${String(now.getMonth() + 1).padStart(2, '0')}`;
+        
+        // 生成唯一文件名
+        const ext = fileName.includes('.') ? fileName.substring(fileName.lastIndexOf('.')) : '';
+        const uniqueId = crypto.randomUUID().replace(/-/g, '');
+        const fullId = uniqueId + ext;
+        const filePath = `images/${yearMonth}/${fullId}`;
+
+        // 获取 LFS 上传信息
+        const huggingfaceAPI = new HuggingFaceAPI(hfChannel.token, hfChannel.repo, hfChannel.isPrivate || false);
+        const uploadInfo = await huggingfaceAPI.getLfsUploadInfo(fileSize, filePath, sha256, fileSample);
+
+        // 返回上传信息
+        return new Response(JSON.stringify({
+            success: true,
+            fullId,
+            filePath,
+            channelName: hfChannel.name,
+            repo: hfChannel.repo,
+            isPrivate: hfChannel.isPrivate || false,
+            ...uploadInfo
+        }), {
+            status: 200,
+            headers: { 'Content-Type': 'application/json' }
+        });
+
+    } catch (error) {
+        console.error('getUploadUrl error:', error.message);
+        return new Response(JSON.stringify({ error: error.message }), {
+            status: 500,
+            headers: { 'Content-Type': 'application/json' }
+        });
+    }
+}