Switch Directors Forecast to use forecasting API instead of direct DB

Replace queryForecast/forecast-db.js with fetch() calls to the
forecasting app's public API (/forecasting/api/public/forecast/revenue
and /forecast/rooms). This removes the need for cross-DB grants and the
FORECAST_DATABASE_URL — all data comes from FORECASTING_API_KEY +
FORECASTING_URL. The DOW-history algorithm is also removed since the
covers model in the forecasting API already handles dry/wet future
forecasts.

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

docker-compose.yml

@@ -5,7 +5,8 @@ services:
       - apparmor=unconfined
     environment:
       - DATABASE_URL=${DATABASE_URL}
-      - FORECAST_DATABASE_URL=${FORECAST_DATABASE_URL:-}
+      - FORECASTING_URL=${FORECASTING_URL:-http://10.10.10.113:3080}
+      - FORECASTING_API_KEY=${FORECASTING_API_KEY:-}
       - CENTRAL_AUTH_SECRET=${CENTRAL_AUTH_SECRET}
       - SETTINGS_URL=${SETTINGS_URL}
       - SETTINGS_SECRET=${SETTINGS_SECRET}