feat: GeoScene frontend POC + Docker deploy for remote host

Migrate maps to @geoscene/core, polish monitoring/alerts UX, fix timeline
basemap flicker and district alert regions, and ship compose/nginx Docker
deploy assets with CBPOA_ROOT data mounts.

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

backend/routers/alerts.py

@@ -13,6 +13,7 @@ from config import DATA_DIR, ALERT_P1_RISK, ALERT_P2_RISK, WUHAN_BOUNDS, LAT_STE
 from models import Alert, AlertResponse
 from utils.date_helpers import get_latest_date, validate_date_format
 from utils.risk import risk_value_to_level
+from utils.district_lookup import district_for_grid
 
 router = APIRouter(prefix="/api/alerts", tags=["alerts"])
 
@@ -95,13 +96,14 @@ def _generate_alerts_cached(date: str) -> List[Alert]:
 
         lat, lon = grid_id_to_center(grid_id)
         risk_level = risk_value_to_level(max_risk)
+        district = district_for_grid(grid_id)
 
         alerts.append(
             Alert(
                 alert_id=f"alert_{date}_{grid_id}",
                 grid_id=grid_id,
-                region="武汉市",
-                street=f"Grid {grid_id}",
+                region=district,
+                street=grid_id,
                 latitude=lat,
                 longitude=lon,
                 risk_value=max_risk,