HexaWetter v1.3.0: Add precipitation map feature, update README, and enhance UI elements

.env.example

@@ -38,6 +38,12 @@ CACHE_TTL_GEOCODE=86400
 CACHE_TTL_WMS_TIMES=120
 CACHE_TTL_HEALTH_SOURCES=90
 CACHE_TTL_DASHBOARD=60
+CACHE_TTL_PRECIP_MAP=900
+
+# Regenvorhersage-Karte (Open-Meteo Gitternetz)
+PRECIP_MAP_HOURS_DEFAULT=24
+PRECIP_MAP_SPAN_DEG=3.0
+PRECIP_MAP_STEP_DEG=0.25
 
 # Security (generate with: python scripts/setup_secrets.py 'your-secure-password')
 API_KEY=