refactor: rename api_gateway → api across workspace, tests, and load crate

- Workspace Cargo.toml: remove web-gateway + api_gateway members, keep api
- trading_service: dep api-gateway → api, update test imports
- testing/api-gateway-load → testing/api-load (crate renamed)
- All test crates: get_api_gateway_addr → get_api_addr + variable renames

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

testing/integration/smoke_tests/mod.rs

@@ -68,7 +68,7 @@ pub mod common {
     }
 
     /// Load API Gateway URL from environment
-    pub fn api_gateway_url() -> String {
+    pub fn api_url() -> String {
         std::env::var("API_GATEWAY_URL")
             .unwrap_or_else(|_| "http://localhost:50051".to_string())
     }

testing/integration/smoke_tests/service_health.rs

@@ -46,9 +46,9 @@ async fn test_trading_service_health() {
 }
 
 #[tokio::test]
-async fn test_api_gateway_health() {
+async fn test_api_health() {
     let result = with_timeout(async {
-        let url = api_gateway_url();
+        let url = api_url();
         println!("Testing API Gateway at {}", url);
 
         // Try gRPC connection
@@ -66,7 +66,7 @@ async fn test_api_gateway_health() {
         }
     }).await;
 
-    skip_if_unavailable!("API Gateway", { result });
+    skip_if_unavailable!("API", { result });
 }
 
 #[tokio::test]
@@ -122,7 +122,7 @@ async fn test_service_ports_listening() {
     println!("🔍 Checking service ports...");
 
     let ports_to_check = vec![
-        (50051, "API Gateway"),  // Primary entry point
+        (50051, "API"),  // Primary entry point
         (50052, "Trading Service"),  // Backend service
         (50053, "Backtesting Service"),
         (50054, "ML Training Service"),
@@ -159,7 +159,7 @@ async fn test_service_response_times() {
 
     let services = vec![
         (trading_service_url(), "Trading Service"),
-        (api_gateway_url(), "API Gateway"),
+        (api_url(), "API"),
     ];
 
     for (url, name) in services {
@@ -197,7 +197,7 @@ async fn test_metrics_endpoints() {
 
     let client = reqwest::Client::new();
     let metrics_ports = vec![
-        (9091, "API Gateway"),
+        (9091, "API"),
         (9092, "Trading Service"),
         (9093, "Backtesting Service"),
         (9094, "ML Training Service"),

testing/integration/standalone/watch_tuning_progress_updated.rs

@@ -1,6 +1,6 @@
 /// Watch tuning progress with live updates (poll every 5 seconds)
 async fn watch_tuning_progress(
-    api_gateway_url: &str,
+    api_url: &str,
     jwt_token: &str,
     job_id: &str,
 ) -> AnyhowResult<()> {
@@ -14,7 +14,7 @@ async fn watch_tuning_progress(
         .context("❌ Invalid job ID format (expected UUID)")?;
 
     // Create gRPC client once (reuse connection)
-    let mut client = MlTrainingServiceClient::connect(api_gateway_url.to_string())
+    let mut client = MlTrainingServiceClient::connect(api_url.to_string())
         .await
         .context("Failed to connect to API Gateway")?;