🐛 fix(api): add Vercel serverless function for Bilibili search suggestions

- Create api/bilibili.ts to handle Bilibili API requests in production
  - Proxy requests to https://s.search.bilibili.com/main/suggest
  - Add proper headers (User-Agent, Referer) to avoid blocking
  - Set CORS headers and cache control (60s)
  - Handle errors gracefully with fallback response
- Update src/utils/suggestions.ts to detect environment
  - Use /bilibili (Vite proxy) in development
  - Use /api/bilibili (Vercel Function) in production
  - Check import.meta.env.DEV to determine environment

This fixes the 404 error in production where Vite proxy is not available.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

api/bilibili.ts

@@ -0,0 +1,49 @@
+import type { VercelRequest, VercelResponse } from '@vercel/node';
+
+export default async function handler(
+  req: VercelRequest,
+  res: VercelResponse
+) {
+  // Only allow GET requests
+  if (req.method !== 'GET') {
+    return res.status(405).json({ error: 'Method not allowed' });
+  }
+
+  const { term } = req.query;
+
+  if (!term || typeof term !== 'string') {
+    return res.status(400).json({ error: 'Missing term parameter' });
+  }
+
+  try {
+    // Request Bilibili search suggestion API
+    const bilibiliUrl = `https://s.search.bilibili.com/main/suggest?term=${encodeURIComponent(term)}`;
+
+    const response = await fetch(bilibiliUrl, {
+      headers: {
+        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
+        'Referer': 'https://www.bilibili.com',
+      },
+    });
+
+    if (!response.ok) {
+      throw new Error(`Bilibili API returned ${response.status}`);
+    }
+
+    const data = await response.json();
+
+    // Set CORS headers
+    res.setHeader('Access-Control-Allow-Origin', '*');
+    res.setHeader('Access-Control-Allow-Methods', 'GET');
+    res.setHeader('Cache-Control', 's-maxage=60, stale-while-revalidate');
+
+    return res.status(200).json(data);
+  } catch (error) {
+    console.error('Bilibili API error:', error);
+    return res.status(500).json({
+      error: 'Failed to fetch suggestions',
+      code: -1,
+      result: { tag: [] }
+    });
+  }
+}

src/utils/suggestions.ts

@@ -22,9 +22,13 @@ export const fetchSuggestions = (engine: string, query: string): Promise<string[
       return;
     }
 
-    // Bilibili uses fetch (via Vite proxy)
+    // Bilibili uses fetch (via Vite proxy in dev, Vercel Function in production)
     if (engine === 'Bilibili') {
-      const url = `/bilibili?term=${encodeURIComponent(query)}`;
+      // In production (Vercel), use /api/bilibili; in development, use /bilibili (Vite proxy)
+      const isDev = import.meta.env.DEV;
+      const url = isDev
+        ? `/bilibili?term=${encodeURIComponent(query)}`
+        : `/api/bilibili?term=${encodeURIComponent(query)}`;
 
       fetch(url)
         .then(response => response.json())