style(theme): 更新网站主题色彩方案与字体配置

- 调整主色调从 #1C1C1C 至 #1A1A1A，优化视觉层次
- 更新背景色系为暖白色调 (#FAFAF7, #F5F4F0 等)
- 配置中文字体栈，添加 serif 字体支持
- 优化文本颜色梯度，提升可读性
- 调整边框颜色，统一水墨风格
- 添加 Google Search Console 验证码配置项
- 新增桌面应用架构专家代理配置文件
- 重构 E2E 测试等待策略，提升稳定性
- 添加回归测试脚本，增强质量保障

src/app/api/contact/route.ts

@@ -0,0 +1,33 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { COMPANY_INFO } from '@/lib/constants';
+
+export async function POST(request: NextRequest) {
+  try {
+    const body = await request.formData();
+
+    const formBody = new URLSearchParams();
+    formBody.append('name', body.get('name') as string);
+    formBody.append('phone', body.get('phone') as string);
+    formBody.append('email', body.get('email') as string);
+    formBody.append('subject', body.get('subject') as string);
+    formBody.append('message', body.get('message') as string);
+    formBody.append('_subject', `网站留言: ${body.get('subject')}`);
+    formBody.append('_captcha', 'false');
+    formBody.append('_template', 'table');
+
+    const response = await fetch(`https://formsubmit.co/ajax/${COMPANY_INFO.email}`, {
+      method: 'POST',
+      headers: { 'Accept': 'application/json' },
+      body: formBody.toString(),
+    });
+
+    const data = await response.json();
+
+    return NextResponse.json(data, { status: response.status });
+  } catch {
+    return NextResponse.json(
+      { success: false, message: '服务器内部错误' },
+      { status: 500 }
+    );
+  }
+}