Add assistant-ui data agent frontend

frontend/app/app/api/claw/files/route.ts

@@ -0,0 +1,48 @@
+import { readFile, stat } from "node:fs/promises";
+import path from "node:path";
+import { accountBaseRoot, getCurrentAccount } from "@/lib/claw-auth";
+
+export const runtime = "nodejs";
+
+export async function GET(req: Request) {
+	const account = await getCurrentAccount();
+	if (!account)
+		return Response.json({ error: "请先登录账号" }, { status: 401 });
+
+	const url = new URL(req.url);
+	const requestedPath = url.searchParams.get("path");
+	if (!requestedPath) {
+		return Response.json({ error: "缺少文件路径" }, { status: 400 });
+	}
+
+	const accountRoot = path.resolve(accountBaseRoot(account.id));
+	const filePath = path.resolve(requestedPath);
+	if (!filePath.startsWith(`${accountRoot}${path.sep}`)) {
+		return Response.json({ error: "文件不在当前账号目录内" }, { status: 403 });
+	}
+
+	try {
+		const fileStat = await stat(filePath);
+		if (!fileStat.isFile()) {
+			return Response.json({ error: "目标不是文件" }, { status: 400 });
+		}
+		const bytes = await readFile(filePath);
+		return new Response(bytes, {
+			headers: {
+				"content-type": contentTypeFor(filePath),
+				"content-disposition": `attachment; filename="${encodeURIComponent(path.basename(filePath))}"`,
+			},
+		});
+	} catch {
+		return Response.json({ error: "文件不存在" }, { status: 404 });
+	}
+}
+
+function contentTypeFor(filePath: string) {
+	const ext = path.extname(filePath).toLowerCase();
+	if (ext === ".json") return "application/json; charset=utf-8";
+	if (ext === ".jsonl" || ext === ".txt" || ext === ".md" || ext === ".csv") {
+		return "text/plain; charset=utf-8";
+	}
+	return "application/octet-stream";
+}