docs: clarify host catalog and cancellation boundaries

Signed-off-by: vastraliu <vastraliu@tencent.com>

Author: vastraliu

docs/architecture/rfcs/manager-runtime-profile-v0.md

@@ -94,3 +94,15 @@ tool/session/continued-execution and settings readback, without a second machine
    fallback state.
 8. An external audience without an existing scoped grant remains `read-only` and exposes the
    effective downgrade accurately.
+
+### Model discovery and native cancellation
+
+The Chat model picker reads the selected host through `GET /api/chat/models`.
+Codex discovery uses its configured CLI and captured home for paginated
+`model/list`, without creating a model Turn. Native Claude discovery projects
+only the host's declared model picker metadata. Catalog availability is not
+proof of inference or model access; empty and unavailable catalogs retain an
+explicit model input, rather than falling back to another host's suggestions.
+Legacy Codex catalog compatibility remains visible in the response and UI.
+Native Chat interruption terminates the invocation's owned process group,
+including wrapper children. It does not target unrelated host sessions.

docs/architecture/rfcs/manager-runtime-profile-v0.zh-CN.md

@@ -79,3 +79,12 @@ R2 补真实工具/会话/连续执行与设置读回；不得新建第二份机
    已撤销的受众权限和前一轮对话的私有 reader。
 7. 桌面和移动 Dashboard 显示有效 profile；配置损坏时显示回退状态。
 8. 外部 audience 在没有既有 scoped grant 时继续 `read-only`，并显示真实降级状态。
+
+### 模型发现与原生取消
+
+Chat 模型选择器通过 `GET /api/chat/models` 读取选定宿主。Codex 使用已配置
+CLI 和启动时固定的 home 分页读取 `model/list`，不创建模型 Turn。原生 Claude
+只投影宿主声明的模型选择元数据。目录可用不代表推理成功或具有模型访问权限；
+目录为空或不可用时保留显式模型输入，不使用其他宿主的推荐项。Codex 旧目录
+兼容处理会在响应和界面中明确显示。原生 Chat 取消会终止该次调用拥有的进程组，
+包括包装器子进程，不影响其他宿主会话。