feat: 新增 frontdoor 执行回环守卫与多项可观测性增强

- 新增 frontdoor_loop_guard 模块，检测并拒绝 execution runtime 回环到本地网关的请求（HTTP 508）
- candidate loop 引入 span tracking、执行尝试日志与流式看门狗超时
- 本地故障转移策略支持从 report_context 加载，新增 append_local_failover_policy_to_value
- runtime tracing 美化：移除 identity 前缀，按 span 深度树形缩进，target 固定宽度展示
- Codex OpenAI CLI 补齐 chatgpt-account-id/x-client-request-id/session_id/conversation_id 请求头
- OpenAI CLI same/cross-format 聚合规则放宽以支持 openai:compact 客户端格式，并过滤 error-like 响应体
- auth/proxy/finalize 日志补充 user_id/api_key_id/api_key_name/balance_remaining 等字段
- 启动日志拆分为 starting/ready/config 三段，新增 resolve_bind_http_base_url
- access_log middleware 将生成的 trace_id 回注到下游请求头
- Cargo.toml 启用 serde_json preserve_order 特性

apps/aether-gateway/src/handlers/proxy/finalize.rs

@@ -87,6 +87,13 @@ pub(super) fn finalize_gateway_response(
         .filter(|value| !value.trim().is_empty())
         .unwrap_or("-")
         .to_string();
+    let auth_context = control_decision.and_then(|decision| decision.auth_context.as_ref());
+    let user_id = auth_context
+        .map(|auth_context| auth_context.user_id.as_str())
+        .unwrap_or("-");
+    let api_key_id = auth_context
+        .map(|auth_context| auth_context.api_key_id.as_str())
+        .unwrap_or("-");
     let status_code = response.status().as_u16();
     emit_admin_audit(
         &mut response,
@@ -106,6 +113,8 @@ pub(super) fn finalize_gateway_response(
             remote_addr = %remote_addr,
             method = %method,
             path = %path_and_query,
+            user_id,
+            api_key_id,
             route_class,
             execution_path,
             dependency_reason = dependency_reason.as_str(),
@@ -124,6 +133,8 @@ pub(super) fn finalize_gateway_response(
             remote_addr = %remote_addr,
             method = %method,
             path = %path_and_query,
+            user_id,
+            api_key_id,
             route_class,
             execution_path,
             dependency_reason = dependency_reason.as_str(),
@@ -142,6 +153,8 @@ pub(super) fn finalize_gateway_response(
             remote_addr = %remote_addr,
             method = %method,
             path = %path_and_query,
+            user_id,
+            api_key_id,
             route_class,
             execution_path,
             dependency_reason = dependency_reason.as_str(),