fix(test): stabilize openai compat oversized-body regression (#839)

* fix(test): stabilize openai compat oversized-body regression

* docs(web): fix stale body limit in CLAUDE.md (1 MB → 10 MB)

CLAUDE.md:200 still documented the pre-#725 body limit of 1 MB, but
server.rs:354 was changed to 10 MB in #725 (image upload support).
Update the documentation to match the actual production value.

src/channels/web/CLAUDE.md

@@ -197,7 +197,7 @@ All responses include:
 - `X-Content-Type-Options: nosniff`
 - `X-Frame-Options: DENY`
 
-**Request body limit:** 1 MB (`DefaultBodyLimit::max(1024 * 1024)`). Larger payloads return 413.
+**Request body limit:** 10 MB (`DefaultBodyLimit::max(10 * 1024 * 1024)`), sized for image uploads (#725). Larger payloads return 413.
 
 ## Pending Approvals
 

tests/openai_compat_integration.rs

@@ -729,21 +729,45 @@ async fn test_no_llm_provider_returns_503() {
 
 #[tokio::test]
 async fn test_chat_completions_body_too_large() {
-    let (addr, _state, _mock_state) = start_test_server().await;
-    let url = format!("http://{}/v1/chat/completions", addr);
+    use axum::{Router, body::Body, extract::DefaultBodyLimit, middleware, routing::post};
+    use tower::ServiceExt;
 
-    // Build a payload over 10 MB (the gateway's DefaultBodyLimit)
+    let mock_state = Arc::new(MockLlmState::default());
+    let llm_provider: Arc<dyn LlmProvider> = Arc::new(MockLlmProvider::new(mock_state));
+    let state = ironclaw::channels::web::test_helpers::TestGatewayBuilder::new()
+        .llm_provider(llm_provider)
+        .build();
+    let auth_state = ironclaw::channels::web::auth::AuthState {
+        token: AUTH_TOKEN.to_string(),
+    };
+
+    let app = Router::new()
+        .route(
+            "/v1/chat/completions",
+            post(ironclaw::channels::web::openai_compat::chat_completions_handler),
+        )
+        .route_layer(middleware::from_fn_with_state(
+            auth_state,
+            ironclaw::channels::web::auth::auth_middleware,
+        ))
+        .layer(DefaultBodyLimit::max(10 * 1024 * 1024))
+        .with_state(state);
+
+    // Build a payload over 10 MB (the gateway's DefaultBodyLimit).
     let big_content = "x".repeat(11 * 1024 * 1024);
-    let resp = client()
-        .post(&url)
-        .bearer_auth(AUTH_TOKEN)
-        .json(&serde_json::json!({
-            "model": "mock-model-v1",
-            "messages": [{"role": "user", "content": big_content}]
-        }))
-        .send()
-        .await
+    let body = serde_json::to_vec(&serde_json::json!({
+        "model": "mock-model-v1",
+        "messages": [{"role": "user", "content": big_content}]
+    }))
+    .unwrap();
+    let req = axum::http::Request::builder()
+        .method("POST")
+        .uri("/v1/chat/completions")
+        .header("authorization", format!("Bearer {}", AUTH_TOKEN))
+        .header("content-type", "application/json")
+        .body(Body::from(body))
         .unwrap();
 
+    let resp = app.oneshot(req).await.unwrap();
     assert_eq!(resp.status(), 413);
 }