feat(codex): 支持compact端点非流式请求，更新请求头与字段清理

- Codex适配器支持compact端点：非流式请求使用application/json Accept头，
  stream_policy根据compact上下文返回FORCE_NON_STREAM
- 更新Codex请求头格式：添加Version/Connection头，header key首字母大写
- 简化include列表处理：normalizer和request_patching统一强制为固定列表
- 清理Codex不支持的字段：truncation、context_management、user
- 默认instructions改为空字符串
- 前端用量页面：用户页面使用前端筛选后总数，避免不必要的后端分页请求

tests/services/test_upstream_stream_policy.py

@@ -3,6 +3,10 @@ from __future__ import annotations
 from dataclasses import dataclass
 from types import SimpleNamespace
 
+from src.services.provider.adapters.codex.context import (
+    CodexRequestContext,
+    set_codex_request_context,
+)
 from src.services.provider.stream_policy import (
     UpstreamStreamPolicy,
     enforce_stream_mode_for_upstream,
@@ -42,6 +46,19 @@ def test_get_upstream_stream_policy_codex_ignores_force_non_stream_config() -> N
     assert get_upstream_stream_policy(ep) == UpstreamStreamPolicy.FORCE_STREAM
 
 
+def test_get_upstream_stream_policy_codex_compact_forces_non_stream() -> None:
+    ep = _DummyEndpoint(
+        api_format="openai:cli",
+        config=None,
+        provider=SimpleNamespace(provider_type="codex"),
+    )
+    try:
+        set_codex_request_context(CodexRequestContext(is_compact=True))
+        assert get_upstream_stream_policy(ep) == UpstreamStreamPolicy.FORCE_NON_STREAM
+    finally:
+        set_codex_request_context(None)
+
+
 def test_enforce_stream_mode_for_upstream_openai_chat_sets_stream_options_usage() -> None:
     body = {"stream": False}
     out = enforce_stream_mode_for_upstream(