feat(docker): prepare portable images with runtime hotel configuration

.env.example

@@ -23,12 +23,14 @@ HOUSEKEEPING_NEXT_PREVIEW_ENABLED=false
 # --- HOTEL & URLS ---
 HOTEL_NAME=EPIC WEB CONTROL
 APP_URL=http://localhost:3002
-NEXT_PUBLIC_APP_URL=http://localhost:3002
 AUTH_URL=http://localhost:3002
 
 # --- IMAGER ---
 IMAGING_UPSTREAM_URL=http://127.0.0.1:3030/imaging
-NEXT_PUBLIC_IMAGER_URL=http://localhost:3002/imaging
+# Runtime values: changing these only requires recreating the container.
+IMAGER_URL=http://127.0.0.1:3030/imaging
+BADGE_URL=/swf/c_images/album1584
+# Legacy NEXT_PUBLIC_IMAGER_URL / NEXT_PUBLIC_BADGE_URL are still read at runtime.
 
 # --- SECURITY & HASHING ---
 AUTH_SECRET=your-super-secret-auth-key-change-this-min-32-chars