feat(weather): OWM-Fallback über Server-.env wenn kein User-Key

Wetter-Proxy auf /api/weather/current nutzt optionalen Nutzer-Key aus
den Einstellungen, sonst OpenWeatherMapAPIKey aus der Umgebung.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/src/routes/weather.ts

@@ -0,0 +1,59 @@
+import { Router } from 'express'
+
+const router = Router()
+
+const requireUser = (req: any, res: any, next: any) => {
+  const userId = req.headers['x-user-id']
+  if (!userId) {
+    return res.status(401).json({ error: 'Unauthorized: X-User-Id header missing' })
+  }
+  req.userId = userId
+  next()
+}
+
+function resolveOwmApiKey(userProvidedKey: unknown): string | null {
+  if (typeof userProvidedKey === 'string' && userProvidedKey.trim()) {
+    return userProvidedKey.trim()
+  }
+  const fromEnv =
+    process.env.OpenWeatherMapAPIKey?.trim() ||
+    process.env.OPENWEATHERMAP_API_KEY?.trim()
+  return fromEnv || null
+}
+
+router.get('/current', requireUser, async (req: any, res) => {
+  try {
+    const { lat, lon, q } = req.query
+    const apiKey = resolveOwmApiKey(req.headers['x-owm-api-key'])
+
+    if (!apiKey) {
+      return res.status(503).json({
+        error: 'No OpenWeatherMap API key configured (user settings or server environment)'
+      })
+    }
+
+    let url: URL
+    if (lat && lon) {
+      url = new URL('https://api.openweathermap.org/data/2.5/weather')
+      url.searchParams.set('lat', String(lat))
+      url.searchParams.set('lon', String(lon))
+    } else if (q && typeof q === 'string' && q.trim()) {
+      url = new URL('https://api.openweathermap.org/data/2.5/weather')
+      url.searchParams.set('q', q.trim())
+    } else {
+      return res.status(400).json({ error: 'lat and lon, or q (location name) is required' })
+    }
+
+    url.searchParams.set('appid', apiKey)
+    url.searchParams.set('units', 'metric')
+
+    const owmRes = await fetch(url)
+    const data = await owmRes.json()
+    return res.status(owmRes.status).json(data)
+  } catch (error: any) {
+    console.error('Error fetching OpenWeatherMap data:', error)
+    return res.status(502).json({ error: error.message || 'Weather lookup failed' })
+  }
+})
+
+export default router