feat(tunnel): 请求体流式传输 & OpenAI CLI 请求 key 排序优化

Hub 端:
- open_local_stream 不再接收 body 参数，改为通过 push_local_request_body 分块推送
- 请求体按 32KB 分帧发送，避免大请求一次性压缩和传输
- local_relay 改为流式解析 envelope 和转发请求体

Proxy 端:
- stream_handler 改为流式传输请求体到上游，不再预先收集完整 body
- upstream_client 请求体类型从 Full<Bytes> 改为 UnsyncBoxBody 以支持流式传输
- dispatcher 将 StreamEnd/StreamError 事件转发给 stream handler

Python 端:
- hub_transport relay envelope 改为异步生成器流式发送
- 提取 reorder_openai_cli_request_prefix_keys 为公共函数
- Codex passthrough 路径也应用稳定的前缀 key 排序

aether-hub/Cargo.lock

@@ -10,7 +10,7 @@ checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
 [[package]]
 name = "aether-hub"
-version = "0.1.8"
+version = "0.1.9"
 dependencies = [
  "async-stream",
  "axum",
@@ -19,6 +19,7 @@ dependencies = [
  "dashmap",
  "flate2",
  "futures-util",
+ "http-body-util",
  "parking_lot",
  "reqwest",
  "serde",