fix: reuse runtime processes across project sessions

Multiple projects could spawn duplicate heavyweight runtimes, while settings
changes and remote reconnection could cancel or strand native conversations.
Share compatible local OpenCode and DeepSeek Harness process owners and
Agent-owned ACP connections, retaining workspace routing, per-session modes,
model attribution, question ownership, targeted cancellation and idle cleanup.

Restore remote pending questions and terminal task projections across reconnect
and desktop restart, and preserve accepted ordinary requests during settings
replacement while cancelling expert-team parents with their replaced scheduler.
Extend regression coverage and Agent type checks. Record measured resource and
real-model validation results, including failures and limitations.

Also include the conversation media-generation design drafts (not an implemented
feature), documentation entry links and dedicated Linux test-directory guidance.
Desktop and Agent changes must be delivered together for shared process results.

Validation: typecheck and lint passed; staged content and documentation links
checked. Prior full regression and live-model evidence are recorded in progress
notes; no new full test suite or model calls were run for this commit.

Release note: 多项目会话现在复用兼容的 OpenCode 和 DeepSeek Harness 进程，减少重复启动并保持工作区、工具和取消隔离。修复远端问答在断线、重启及配置更新后的恢复与状态同步问题，Desktop 与 Agent 需配套更新。

docs/features/remote-host/README.md

@@ -11,3 +11,7 @@
 | [远程环境准备技术设计](./environment-provisioning-technical-design.md) | Host 下载、GoodBuddy 传输、安装事务、更新和恢复边界 |
 
 现有文档包含产品、功能逻辑和进度事实，后续修改远程功能时再按标准职责拆分。
+
+跨会话共享 OpenCode 进程、ACP 连接与模型桥的实现设计，见
+[Runtime 进程复用技术设计](../assistant-workbar/runtime-process-reuse-technical-design.md#6-ssh-opencode-与-agent)。
+当前实现尚未发布；验收状态见[工作栏进度](../assistant-workbar/progress.md#2026-09-14-runtime-进程复用实施中)。

docs/features/remote-host/technical-design.md

@@ -319,6 +319,9 @@ Execute 直接启动已签名 Runtime：
   自动重放。插件随 OpenCode 实例释放临时端口，helper 退出时删除插件文件。
   以上只适用于当前 Agent 管理的 SSH OpenCode 生产路径，不声明任意 ACP 服务的问答兼容性。
   真实二进制、SSH 传输和取消验证见[工作栏进度](../assistant-workbar/progress.md#2026-09-13-托管-ssh-原生问答)。
+  未发布进程复用源码补齐 Desktop 重启后的多任务并行附加、实时待答快照及 Main 答案
+  持久化，详见[恢复与终态投影](../assistant-workbar/runtime-process-reuse-technical-design.md#63-恢复与终态投影)；
+  不把该待答投影当作 durable transcript 或旧版本已经支持的行为。
 - ACP 工具结果同时支持文本 `content` 和 `rawOutput.output`，移除 OpenCode 的
   `<task><task_result>` 外层包装后渲染正文。恢复已有子代理时使用 ACP 所带的所属
   `toolCallId` 继续路由，不等待新的父 Task metadata，也不重放模型请求。