feat: add /api/download endpoint for APK file downloads

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

app/api/download/route.ts

@@ -0,0 +1,55 @@
+// app/api/download/route.ts
+import { NextResponse } from 'next/server';
+import path from 'path';
+import fs from 'fs';
+import { RESOURCE_PATH } from '@/lib/constants';
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const project = searchParams.get('project');
+  const version = searchParams.get('version');
+  const filename = searchParams.get('filename');
+
+  if (!project || !version || !filename) {
+    return NextResponse.json(
+      { error: 'Project, version, and filename parameters are required' },
+      { status: 400 }
+    );
+  }
+
+  // 安全检查：确保 filename 不包含路径遍历字符
+  if (filename.includes('..') || filename.includes('/') || filename.includes('\\')) {
+    return NextResponse.json(
+      { error: 'Invalid filename' },
+      { status: 400 }
+    );
+  }
+
+  const filePath = path.join(RESOURCE_PATH, project, version, 'apks', filename);
+
+  try {
+    // 检查文件是否存在
+    if (!fs.existsSync(filePath)) {
+      return NextResponse.json(
+        { error: 'File not found' },
+        { status: 404 }
+      );
+    }
+
+    // 读取文件并流式返回
+    const file = fs.readFileSync(filePath);
+
+    return new NextResponse(file, {
+      headers: {
+        'Content-Type': 'application/vnd.android.package-archive',
+        'Content-Disposition': `attachment; filename="${filename}"`,
+        'Content-Length': file.length.toString(),
+      },
+    });
+  } catch (error) {
+    return NextResponse.json(
+      { error: 'Failed to download file' },
+      { status: 500 }
+    );
+  }
+}