refactor: item 29 cleanup

C14 C16 C17 C18 C20 A11 A15 X10 X12 X15: dead Steam count code, GameNames, steamIdText, one query per game for the finished estimate, no API versioning config, open-in-view off, CORS from APP_FRONTEND_URL, non-root image, prune only up to the highest known id.

Dockerfile

@@ -36,5 +36,9 @@ EXPOSE 8090
 # Copy the compiled jar file from the builder stage
 COPY --from=builder /app/target/*.jar app.jar
 
+# No root in the container
+RUN addgroup -S app && adduser -S app -G app
+USER app
+
 # Run the application
 ENTRYPOINT ["java", "-jar", "app.jar"]