Fix docker-compose.yml invalid empty environment mapping

Move environment block to comments since all values were commented out.
An empty environment: key with only comments is invalid YAML.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker-compose.yml

@@ -23,10 +23,10 @@ services:
     restart: always
     ports:
       - "8080:8080"
-    environment:
-      # Testing overrides (uncomment to enable):
-      # FORCE_UPDATE_AVAILABLE: "1"        # Always show update available
-      # FAKE_LATEST_VERSION: "99.0.0"      # Fake a newer version
+    # Environment variables for testing (uncomment to enable):
+    # environment:
+    #   FORCE_UPDATE_AVAILABLE: "1"        # Always show update available
+    #   FAKE_LATEST_VERSION: "99.0.0"      # Fake a newer version
     volumes:
       # Mount entire app directory for persistence
       - .:/app