Add: München als 3. Wetter-Location + Wetter-Detail-Modal

- München als tertiärer Standort (iris-Akzent) hinzugefügt
- Klick auf WeatherCard öffnet Detail-Modal mit:
  - 24h stündliche Prognose (horizontal scrollbar)
  - 7-Tage-Vorhersage mit Temperaturbalken
  - Wind, Feuchte, Sonnenauf/-untergang
- Backend: 7-Tage statt 3-Tage Forecast, 24 Hourly-Slots pro Standort
- Backend: forecast_3day → forecast Feldname-Konsistenz
- Dashboard: 3-Spalten Wetter-Grid statt 4 (HourlyForecast → Modal)
- Admin: Tertiärer Standort konfigurierbar
- THERMAL Design: iris glow, modal animation, Portal-basiertes Modal

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/config.py

@@ -37,6 +37,7 @@ class Settings:
     # --- Weather ---
     weather_location: str = "Leverkusen"
     weather_location_secondary: str = "Rab,Croatia"
+    weather_location_tertiary: str = "München"
     weather_cache_ttl: int = 1800
 
     # --- Home Assistant ---
@@ -94,6 +95,7 @@ class Settings:
         # Legacy ENV support — used for first-run seeding
         s.weather_location = os.getenv("WEATHER_LOCATION", s.weather_location)
         s.weather_location_secondary = os.getenv("WEATHER_LOCATION_SECONDARY", s.weather_location_secondary)
+        s.weather_location_tertiary = os.getenv("WEATHER_LOCATION_TERTIARY", s.weather_location_tertiary)
         s.ha_url = os.getenv("HA_URL", s.ha_url)
         s.ha_token = os.getenv("HA_TOKEN", s.ha_token)
         s.ha_enabled = bool(s.ha_url)
@@ -151,6 +153,7 @@ class Settings:
                 if itype == "weather":
                     self.weather_location = cfg.get("location", self.weather_location)
                     self.weather_location_secondary = cfg.get("location_secondary", self.weather_location_secondary)
+                    self.weather_location_tertiary = cfg.get("location_tertiary", self.weather_location_tertiary)
 
                 elif itype == "news":
                     self.news_max_age_hours = int(cfg.get("max_age_hours", self.news_max_age_hours))