refactor: repartition server-side and client-side code

app/.server/llm/tools/index.ts

@@ -0,0 +1,17 @@
+import type { Tool, ToolSet } from 'ai';
+import { serperTool } from './serper';
+import { weatherTool } from './weather';
+
+export const tools: () => ToolSet = () => {
+  const tools: Record<string, Tool> = {};
+
+  if (process.env.SERPER_API_KEY) {
+    tools.serper = serperTool;
+  }
+
+  if (process.env.WEATHER_API_KEY) {
+    tools.weather = weatherTool;
+  }
+
+  return tools;
+};