feat(pool,admin): 拆分调度维度、重构调度 UI 与增强配置导入导出

调度维度:
- 新增 cache_affinity/free_first/team_first/plus_first/load_balance 五个独立维度
- 将 free_team_first 标记为 hidden，保留后向兼容但不再显示
- Registry 新增 hidden 属性，_helpers 新增 plus_only 优先级评分

前端调度对话框:
- 分配模式（互斥组）独立为按钮组选择，策略调度保留拖拽排序
- 默认调度从 LRU 轮转改为缓存亲和
- 提取 buildPresetListItem/insertMissingByPreferredOrder 消除重复代码

配置导入导出:
- 导出时 api_formats 支持规范化、去重与 None 回退到 Provider 端点
- 导入时兼容 supported_endpoints 别名与历史 None 语义
- 新增 test_admin_system_key_formats 单元测试

tests/unit/test_admin_system_key_formats.py

@@ -0,0 +1,61 @@
+from src.api.admin.system import AdminExportConfigAdapter, AdminImportConfigAdapter
+
+
+def test_export_key_api_formats_falls_back_to_provider_endpoints_when_none() -> None:
+    adapter = AdminExportConfigAdapter()
+
+    result = adapter._resolve_export_key_api_formats(
+        None,
+        ["claude:chat", "openai:cli"],
+    )
+
+    assert result == ["claude:chat", "openai:cli"]
+
+
+def test_export_key_api_formats_keeps_explicit_empty_list() -> None:
+    adapter = AdminExportConfigAdapter()
+
+    result = adapter._resolve_export_key_api_formats(
+        [],
+        ["openai:chat"],
+    )
+
+    assert result == []
+
+
+def test_export_key_api_formats_normalizes_and_deduplicates() -> None:
+    adapter = AdminExportConfigAdapter()
+
+    result = adapter._resolve_export_key_api_formats(
+        [" OPENAI:CHAT ", "openai:chat", "openai:cli", "bad-format"],
+        ["claude:chat"],
+    )
+
+    assert result == ["openai:chat", "openai:cli"]
+
+
+def test_import_key_api_formats_uses_supported_endpoints_alias() -> None:
+    result = AdminImportConfigAdapter._extract_import_key_api_formats(
+        {"supported_endpoints": ["openai:chat"]},
+        {"openai:chat", "openai:cli"},
+    )
+
+    assert result == ["openai:chat"]
+
+
+def test_import_key_api_formats_falls_back_to_provider_endpoints_when_none() -> None:
+    result = AdminImportConfigAdapter._extract_import_key_api_formats(
+        {"api_formats": None},
+        {"openai:chat", "claude:cli"},
+    )
+
+    assert result == ["claude:cli", "openai:chat"]
+
+
+def test_import_key_api_formats_keeps_explicit_empty_list() -> None:
+    result = AdminImportConfigAdapter._extract_import_key_api_formats(
+        {"api_formats": []},
+        {"openai:chat"},
+    )
+
+    assert result == []