[Desolate-Jix]

Pi 1.2.0 can resolve the documented legacy DeepSeek Flash selection with text-only metadata, causing MCP images to be removed before the provider request. The Host extension uses the public session/turn hooks to select a copy of the native canonical model with the original alias ID, before image conversion. Explicit alias declarations and native/extension Provider registrations retain precedence; the selected endpoint, authentication and model ID remain native.

The compatibility repair is optional. A registry error can belong to an unrelated Provider rather than to models.json parsing. Such errors, unreadable/malformed declarations, an unavailable canonical model or a rejected/failed setModel now retain Pi's native selection, skip the repair for that Work and emit one fixed, sanitized warning. They do not become a fatal extension_error. The Host's normal extension-error handling is unchanged.

Validation of the review revision:

• Native SDK metadata suite: 24 passed, retaining the previous 17 cases and adding error-boundary/multi-turn coverage.
• Provider regression suite: 21 passed. Main's combined run: 45 passed; these counts overlap and are not additive.
• Native TypeScript typecheck and git diff --check passed.
• Regression RED on the unchanged production revision: 9 failed / 15 passed. The corrected revision covers unrelated malformed Provider configuration, declaration read/parse failures before and after native loading, setModel rejection/exception, explicit configuration precedence, repeated startup binding and two image-bearing turns. Failure cases preserve selection, emit no fatal extension_error, notify once and make no network requests.

These checks use the actual Pi 1.2.0 SDK and a deterministic completion stream. They do not claim a new desktop run, external model accuracy or raw provider HTTP capture. Remote CI on review commit 5b3a434 completed successfully: all 15 reported check runs passed. Earlier CI records remain associated with their original heads.

[Lucas1479]

复核结论：核心元数据修复方向正确，但下面这处 P2 请先修改，完成后再请求重新审查；当前版本暂不建议合并。

[P2] 不要把无关 provider 的错误升级成整个 Pi Work 的失败

核验提交：12da7e85c2d1ad61b4ce888e24acc2cb72c56265。model-metadata.ts:39–45 将任意 registry.getError() 转成声明读取失败，并缓存这个 Error；启动和以后每轮都会再次抛出。

Pi 1.2.0 的 getError() 不仅包含 models.json 读取/解析错误，还汇总 provider composition errors 和 availability refresh errors。使用本 PR 的离线 SDK 框架，加入缺少 baseUrl 的无关 provider 即可复现：

{"providers":{"local-llm":{"api":"openai-completions","models":[{"id":"fixture"}]}}}

实测：deepseek-flash 仍可解析；registry 报 Provider local-llm: "baseUrl" is required when defining custom models.；扩展在启动和下一轮各报一次声明读取失败；图片转换数量为 0，网络请求次数为 0。

影响超出了图片兼容：pi.py:337–338 将 extension_error 转成 PiTransportError，已提交运行随后进入 orphaned。默认旧别名路径因此会被一个无关 provider 的错误打断。

请在这段可选兼容逻辑的边界修复：不要把全局 registry 错误等同于声明读取失败；无法可靠判断声明或完成修补时，保留 Pi 原生选择、跳过修补，并通过 ctx.ui.notify 给出一次不含配置内容的提示。真正相关的声明读取/解析失败也不应由这项可选修补升级成致命扩展错误。不要为此全局吞掉 Host 的 extension_error。

请补回归用例，覆盖无关 provider 配错、声明读取/解析失败及多轮行为，验证没有致命 extension_error、提示不重复，并继续保留显式别名/Provider 配置的优先权。现有 17 项 SDK 测试和 typecheck 通过，但未覆盖这一错误边界。