[JasonW404]

统一 Agent、普通会话、Workbench 和创建助手的模型参数保存与调用来源。

• 按模型出口 → Agent → 会话分层覆盖，预检、已有会话 GET/PATCH 和运行使用一致的有效配置。
• 前后端同步采用 Workbench schema 4 和 canonical 偏好，补齐真实模型列表字段映射及 Agent 编辑器保存、重开与无修改确认。
• Token 长度限制由模型管理配置；迁移历史 Workbench 数据，保留历史参数读取转换。
• 恢复 Agent 订阅依赖的会话读取导出，迁移 D2 正式用例与共享 helper，并覆盖已有会话预算修改、清除和续调。

验证：本轮定向 Python 41 项、前端 46 项及 TypeScript 检查通过；D2/D3 正式用例通过；独立 AMD64 镜像部署及真实 Qwen/Phoenix 参数保存、修改、续调验证通过。本轮浏览器交互复验因控制工具不可用尚未完成。最新 CI 全部通过：23,597 passed、32 skipped，总覆盖率 92.1%；Codecov 最新报告显示所有修改且可覆盖的行均已覆盖。

目标分支：develop；后续：#4122、#4097。

[codecov]

Codecov Report

❌ Patch coverage is 93.66667% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...ckend/management/services/agent/preparation/run.py	90.69%	1 Missing and 3 partials ⚠️
backend/management/services/agent/reasoning.py	77.77%	2 Missing and 2 partials ⚠️
backend/management/services/agent/subscription.py	75.00%	2 Missing and 2 partials ⚠️
backend/contracts/agent.py	85.71%	1 Missing and 1 partial ⚠️
backend/management/services/agent/run.py	88.88%	0 Missing and 1 partial ⚠️
...agement/services/conversation/model_preferences.py	97.36%	1 Missing ⚠️
backend/management/services/model/run_controls.py	97.22%	0 Missing and 1 partial ⚠️
backend/services/nl2agent_service.py	66.66%	0 Missing and 1 partial ⚠️
backend/services/nl2skill_service.py	0.00%	0 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!