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

crates/aether-data/adapters/postgres/src/usage/queries/list_recent_usage_audits_prefix.sql

@@ -185,6 +185,7 @@ SELECT
       OR NULLIF(BTRIM("usage".request_metadata->>'provider_actual_service_tier'), '') IS NOT NULL
       OR ("usage".request_metadata->>'client_requested_stream') IN ('true', 'false')
       OR ("usage".request_metadata->>'upstream_is_stream') IN ('true', 'false')
+      OR ("usage".request_metadata->>'websocket_mode') IN ('true', 'false')
       THEN jsonb_strip_nulls(jsonb_build_object(
         'client_ip',
         NULLIF(BTRIM("usage".request_metadata->>'client_ip'), ''),
@@ -213,6 +214,12 @@ SELECT
           WHEN ("usage".request_metadata->>'upstream_is_stream') IN ('true', 'false')
             THEN ("usage".request_metadata->>'upstream_is_stream')::boolean
           ELSE NULL
+        END,
+        'websocket_mode',
+        CASE
+          WHEN ("usage".request_metadata->>'websocket_mode') IN ('true', 'false')
+            THEN ("usage".request_metadata->>'websocket_mode')::boolean
+          ELSE NULL
         END
       ))::json
     ELSE NULL::json

crates/aether-data/adapters/postgres/src/usage/queries/list_usage_audits_prefix.sql

@@ -185,6 +185,7 @@ SELECT
       OR NULLIF(BTRIM("usage".request_metadata->>'provider_actual_service_tier'), '') IS NOT NULL
       OR ("usage".request_metadata->>'client_requested_stream') IN ('true', 'false')
       OR ("usage".request_metadata->>'upstream_is_stream') IN ('true', 'false')
+      OR ("usage".request_metadata->>'websocket_mode') IN ('true', 'false')
       THEN jsonb_strip_nulls(jsonb_build_object(
         'client_ip',
         NULLIF(BTRIM("usage".request_metadata->>'client_ip'), ''),
@@ -213,6 +214,12 @@ SELECT
           WHEN ("usage".request_metadata->>'upstream_is_stream') IN ('true', 'false')
             THEN ("usage".request_metadata->>'upstream_is_stream')::boolean
           ELSE NULL
+        END,
+        'websocket_mode',
+        CASE
+          WHEN ("usage".request_metadata->>'websocket_mode') IN ('true', 'false')
+            THEN ("usage".request_metadata->>'websocket_mode')::boolean
+          ELSE NULL
         END
       ))::json
     ELSE NULL::json

crates/aether-data/adapters/postgres/src/usage/tests.rs

@@ -3221,6 +3221,8 @@ fn usage_sql_uses_json_null_placeholders_for_usage_payload_columns() {
         assert!(sql.contains("request_metadata->>'provider_reasoning_effort'"));
         assert!(sql.contains("request_metadata->>'provider_service_tier'"));
         assert!(sql.contains("request_metadata->>'provider_actual_service_tier'"));
+        assert!(sql.contains("request_metadata->>'websocket_mode'"));
+        assert!(sql.contains("'websocket_mode'"));
         assert!(sql.contains("AS client_family"));
         assert!(sql.contains("request_metadata->'client_session_affinity'->>'client_family'"));
         assert!(sql.contains("request_metadata->>'client_family'"));