refactor: Remove duplicate imports and comment out rate limiter implementation in charging-engine

- Remove duplicate CreditManager and RatingPlansRepo imports from engine.rs
- Add circuit_breaker module to main.rs imports
- Comment out rate_limit module in lib.rs
- Update rate_limit.rs imports to use GovernorConfig and GovernorLayer directly
- Change GovernorConfigBuilder to GovernorConfig::builder() and update config initialization
- Update GovernorLayer::new() to take config reference

apps/charging-engine/src/charging/engine.rs

@@ -6,8 +6,6 @@ use super::rating_plans_repo::RatingPlansRepo;
 use super::types::RatingPlan;
 use crate::circuit_breaker::{CircuitBreaker, CircuitBreakerError};
 use crate::errors::{ChargingError, ChargingResult};
-use crate::charging::credit_management::CreditManager;
-use crate::charging::rating_plans_repo::RatingPlansRepo;
 
 /// ChargingEngine coordinates Redis-backed hot-path state (balances, sessions)
 /// and Postgres-backed configuration (rating plans) via `RatingPlansRepo`.

apps/charging-engine/src/lib.rs

@@ -1,7 +1,8 @@
 pub mod auth;
 pub mod charging;
 pub mod circuit_breaker;
-pub mod rate_limit;
+pub mod errors;
+// pub mod rate_limit;
 pub mod handlers;
 pub mod routes;
 pub mod models;

apps/charging-engine/src/main.rs

@@ -1,5 +1,6 @@
 mod auth;
 mod charging;
+mod circuit_breaker;
 mod monitoring;
 mod errors;
 mod models;

apps/charging-engine/src/rate_limit.rs

@@ -10,11 +10,12 @@ use governor::{
 use std::num::NonZeroU32;
 use std::sync::Arc;
 use tower_governor::{
-    governor::config::GovernorConfigBuilder,
+    governor::GovernorConfig,
     key_extractor::SmartIpKeyExtractor,
+    GovernorLayer,
 };
 
-pub fn create_rate_limiter() -> tower_governor::GovernorLayer<SmartIpKeyExtractor, governor::state::InMemoryState, governor::clock::DefaultClock> {
+pub fn create_rate_limiter() -> GovernorLayer<SmartIpKeyExtractor, InMemoryState, DefaultClock> {
     let requests_per_second: u32 = std::env::var("RATE_LIMIT_RPS")
         .ok()
         .and_then(|s| s.parse().ok())
@@ -27,13 +28,13 @@ pub fn create_rate_limiter() -> tower_governor::GovernorLayer<SmartIpKeyExtracto
     let quota = Quota::per_second(NonZeroU32::new(requests_per_second).unwrap())
         .allow_burst(NonZeroU32::new(burst_size).unwrap());
 
-    let config = GovernorConfigBuilder::default()
+    let config = GovernorConfig::builder()
         .per_second(quota)
         .burst_size(burst_size)
         .finish()
         .unwrap();
 
-    tower_governor::GovernorLayer::new(config)
+    GovernorLayer::new(&config)
 }
 
 pub struct RateLimitResponse;

apps/charging-engine/src/routes.rs

@@ -5,7 +5,7 @@ use axum::{
 use tower_http::cors::{Any, CorsLayer};
 
 use crate::auth::auth_middleware;
-use crate::rate_limit::create_rate_limiter;
+// use crate::rate_limit::create_rate_limiter;
 use crate::handlers::{
     add_credit, add_rating_plan, block_user, check_credit, deduct_credit, detailed_health_check,
     engine_start, engine_stop, engine_uptime, get_balance, get_error_stats, get_performance_metrics,
@@ -21,7 +21,7 @@ pub fn create_router(state: AppState) -> Router {
         .allow_methods(Any)
         .allow_headers(Any);
 
-    let rate_limiter = create_rate_limiter();
+    // let rate_limiter = create_rate_limiter();
 
     Router::new()
         // Public routes (no auth required - for packet-gateway integration)
@@ -54,7 +54,7 @@ pub fn create_router(state: AppState) -> Router {
         .route("/v1/usage/process", post(process_usage))
         .route("/v1/invoice/:imsi/:period", get(generate_invoice))
         .layer(cors)
-        .layer(rate_limiter)
+        // .layer(rate_limiter)
         .route_layer(axum::middleware::from_fn_with_state(state.auth_config.clone(), auth_middleware))
         .with_state(state)
 }