feat: 对接生图功能

Co-authored-by: Copilot <copilot@github.com>

server/api/images/generate.post.ts

@@ -0,0 +1,44 @@
+import { consola } from "consola";
+
+import type {
+  IImageGenerateData,
+  IImageGenerateRequest
+} from "#shared/types/openai";
+import { isUnauthorizedError } from "~~/server/utils";
+
+export default defineEventHandler(async (event) => {
+  const requestBody = await readBody<Partial<IImageGenerateRequest> | null>(
+    event
+  );
+
+  // 只接受 JSON 对象，避免数组、字符串等无效 body 被用于生成请求。
+  if (
+    requestBody !== null &&
+    (typeof requestBody !== "object" || Array.isArray(requestBody))
+  ) {
+    return createErrorResponse(400, "请求体必须是 JSON 对象");
+  }
+
+  const prompt = requestBody?.prompt?.trim();
+  if (!prompt) {
+    return createErrorResponse(400, "请输入图片描述");
+  }
+
+  try {
+    const apiKey = await getAiArtStudioTokenKey(event);
+    const result = await askImg({
+      apiKey,
+      prompt
+    });
+
+    consola.info("图片生成成功", { prompt, imageUrl: result.imageUrl });
+    return createSuccessResponse<IImageGenerateData>(result, "图片生成成功");
+  } catch (error) {
+    if (isUnauthorizedError(error)) {
+      clearNewApiAuthCookies(event);
+      return createErrorResponse(401, "未登录");
+    }
+
+    return createUpstreamErrorResponse(error, "图片生成失败");
+  }
+});