feat(gateway): Codex/OpenAI Responses WebSocket 代理模式

在 /v1/responses 上支持 WebSocket 升级，把客户端帧中继到上游 Codex /
OpenAI Responses WebSocket 端点，同时保持既有的路由、鉴权、配额与用量
语义：

- 路由与准入：control/route/ai.rs 识别 WebSocket 升级请求；
  websocket/ingress.rs 复用 API Key 鉴权、IP 规则与并发许可，并引入
  独立的 WebSocket 连接许可
- 中继：websocket/responses/* 按 connection / session / turn 分层，
  帧解析归一化、socket 写入有界、continuation 保持调度亲和性
- 配额：orchestration/codex_quota_breaker.rs 在账号配额耗尽时熔断并
  自动恢复，不再直接断开客户端连接
- 用量：每个 turn 的终态用量落库，request_metadata 记录
  websocket_mode / websocket_transport，管理端与 usage 视图暴露
  is_websocket
- 管理端：provider 可配置 Responses WebSocket 开关

apps/aether-gateway/src/handlers/shared/catalog.rs

@@ -967,6 +967,12 @@ fn build_codex_quota_status_snapshot(
     let credits_unlimited = metadata
         .get("credits_unlimited")
         .and_then(admin_provider_quota_pure::coerce_json_bool);
+    let allowed = metadata
+        .get("allowed")
+        .and_then(admin_provider_quota_pure::coerce_json_bool);
+    let limit_reached = metadata
+        .get("limit_reached")
+        .and_then(admin_provider_quota_pure::coerce_json_bool);
     let reset_credits = build_codex_reset_credits_status_snapshot(metadata, observed_at_unix_secs);
 
     let windows = [
@@ -996,6 +1002,8 @@ fn build_codex_quota_status_snapshot(
         && credits_has_credits.is_none()
         && credits_balance.is_none()
         && credits_unlimited.is_none()
+        && allowed.is_none()
+        && limit_reached.is_none()
         && reset_credits.is_none()
         && observed_at_unix_secs.is_none()
     {
@@ -1031,11 +1039,19 @@ fn build_codex_quota_status_snapshot(
         .filter_map(admin_provider_quota_pure::coerce_json_u64)
         .min();
     let reset_at = quota_windows_min_reset_at(&primary_windows);
-    let exhausted_by_credits = primary_windows.is_empty()
+    let explicitly_blocked = allowed == Some(false) || limit_reached == Some(true);
+    let explicitly_available =
+        !explicitly_blocked && (allowed == Some(true) || limit_reached == Some(false));
+    let exhausted_by_credits = !explicitly_available
+        && primary_windows.is_empty()
         && credits_unlimited != Some(true)
         && credits_has_credits == Some(false);
-    let exhausted_by_window = usage_ratio.is_some_and(|value| value >= 1.0 - 1e-6);
-    let exhausted = exhausted_by_credits || exhausted_by_window;
+    let exhausted_by_window =
+        !explicitly_available && usage_ratio.is_some_and(|value| value >= 1.0 - 1e-6);
+    let exhausted_by_signal = admin_provider_quota_pure::codex_rate_limit_metadata_exhausted(
+        &Value::Object(metadata.clone()),
+    );
+    let exhausted = exhausted_by_signal || exhausted_by_credits || exhausted_by_window;
 
     let mut credits = Map::new();
     if let Some(value) = credits_has_credits {
@@ -1048,7 +1064,9 @@ fn build_codex_quota_status_snapshot(
         credits.insert("unlimited".to_string(), json!(value));
     }
 
-    let reason = if exhausted_by_credits {
+    let reason = if exhausted_by_signal {
+        Some("上游已拒绝继续使用该账号")
+    } else if exhausted_by_credits {
         Some("无可用积分")
     } else if exhausted_by_window {
         Some("额度窗口已耗尽")
@@ -1071,6 +1089,8 @@ fn build_codex_quota_status_snapshot(
         "reset_at": reset_at,
         "reset_seconds": reset_seconds,
         "plan_type": plan_type,
+        "allowed": allowed,
+        "limit_reached": limit_reached,
         "credits": if credits.is_empty() {
             Value::Null
         } else {
@@ -3833,6 +3853,28 @@ mod tests {
         );
     }
 
+    #[test]
+    fn sync_provider_key_quota_status_snapshot_honors_codex_limit_signal() {
+        let payload = sync_provider_key_quota_status_snapshot(
+            None,
+            "codex",
+            Some(&json!({
+                "codex": {
+                    "updated_at": 1_775_800_000u64,
+                    "allowed": false,
+                    "limit_reached": true
+                }
+            })),
+            "websocket_response_body",
+        )
+        .expect("explicit Codex limit signal should build a quota snapshot");
+
+        assert_eq!(payload.pointer("/quota/code"), Some(&json!("exhausted")));
+        assert_eq!(payload.pointer("/quota/exhausted"), Some(&json!(true)));
+        assert_eq!(payload.pointer("/quota/allowed"), Some(&json!(false)));
+        assert_eq!(payload.pointer("/quota/limit_reached"), Some(&json!(true)));
+    }
+
     #[test]
     fn sync_provider_key_quota_status_snapshot_drops_codex_usage_state_when_window_resets() {
         let current_status_snapshot = json!({