♻️ refactor: reorganize project structure and centralize search engine config

- Move all source files from root to src/ directory for better organization
- Create src/config/searchEngines.ts to centralize search engine configurations
  - Define unified SearchEngineConfig interface
  - Support both JSONP and Fetch request methods
  - Implement response parsers for Google, Baidu, Bing, DuckDuckGo, and Bilibili
- Refactor src/utils/suggestions.ts to use centralized config
  - Simplify code from 126 lines to 81 lines
  - Support hybrid JSONP/Fetch mode (Bilibili uses Fetch via Vite proxy)
  - Remove duplicate URL construction and parsing logic
- Update path alias configuration
  - Change @/* from ./* to ./src/* in tsconfig.json
  - Update vite.config.ts alias to point to ./src
- Add Bilibili proxy configuration in vite.config.ts for development
- Remove Bilibili rewrites from vercel.json (use Vite proxy instead)
- Add @vercel/node to devDependencies
- Remove unused files: README.md, i18n/README.md, metadata.json, vite-env.d.ts

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

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

src/utils/suggestions.ts

@@ -0,0 +1,81 @@
+import {
+  getSearchEngineConfig,
+  buildJsonpUrl,
+  type SearchEngineType
+} from '@/config/searchEngines';
+
+let callbackCount = 0;
+
+/**
+ * Fetch search suggestions (supports hybrid JSONP and Fetch mode)
+ */
+export const fetchSuggestions = (engine: string, query: string): Promise<string[]> => {
+  return new Promise((resolve) => {
+    if (!query || !query.trim()) {
+      resolve([]);
+      return;
+    }
+
+    const config = getSearchEngineConfig(engine as SearchEngineType);
+    if (!config) {
+      resolve([]);
+      return;
+    }
+
+    // Bilibili uses fetch (via Vite proxy)
+    if (engine === 'Bilibili') {
+      const url = `/bilibili?term=${encodeURIComponent(query)}`;
+
+      fetch(url)
+        .then(response => response.json())
+        .then(data => {
+          try {
+            const suggestions = config.parseResponse(data);
+            resolve(suggestions);
+          } catch (e) {
+            resolve([]);
+          }
+        })
+        .catch(() => {
+          resolve([]);
+        });
+      return;
+    }
+
+    // Other engines use JSONP
+    const callbackName = `jsonp_cb_${Date.now()}_${callbackCount++}`;
+    const script = document.createElement('script');
+    let timeoutId: any;
+
+    const cleanup = () => {
+      if ((window as any)[callbackName]) delete (window as any)[callbackName];
+      if (document.body.contains(script)) document.body.removeChild(script);
+      if (timeoutId) clearTimeout(timeoutId);
+    };
+
+    // 3 seconds timeout
+    timeoutId = setTimeout(() => {
+      cleanup();
+      resolve([]);
+    }, 3000);
+
+    // Set global callback function
+    (window as any)[callbackName] = (data: any) => {
+      cleanup();
+      try {
+        const suggestions = config.parseResponse(data);
+        resolve(suggestions);
+      } catch (e) {
+        resolve([]);
+      }
+    };
+
+    // Build URL and make request
+    script.src = buildJsonpUrl(config, query, callbackName);
+    script.onerror = () => {
+      cleanup();
+      resolve([]);
+    };
+    document.body.appendChild(script);
+  });
+};