refactor: use tool() and organize by file (#721)

Co-authored-by: Marcus Schiesser <mail@marcusschiesser.de>

lib/ai/tools/get-weather.ts

@@ -0,0 +1,18 @@
+import { tool } from 'ai';
+import { z } from 'zod';
+
+export const getWeather = tool({
+  description: 'Get the current weather at a location',
+  parameters: z.object({
+    latitude: z.number(),
+    longitude: z.number(),
+  }),
+  execute: async ({ latitude, longitude }) => {
+    const response = await fetch(
+      `https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}&current=temperature_2m&hourly=temperature_2m&daily=sunrise,sunset&timezone=auto`,
+    );
+
+    const weatherData = await response.json();
+    return weatherData;
+  },
+});