docs(coding-teacher): integrate read-only project context repair

.project-docs/20-architecture/module-map.md

@@ -4,7 +4,7 @@
 
 | Path | Responsibility | Owner Notes |
 |---|---|---|
-| `electron/coding-teacher/**`, `electron/api/routes/coding-teacher.ts`, `shared/coding-teacher.ts`, and `src/pages/Chat/Teacher*.tsx` | Main-owned 云配置、来源上下文、本机话题、模型调用、Host API/SSE、独立右侧答疑与运营试聊 | 无 Pi worker 或工具；固定发布版本，账号/项目/来源会话隔离。见 [teacher ADR](../10-decisions/ADR-2026-09-22-coding-teacher.md)。 |
+| `electron/coding-teacher/**`, `electron/api/routes/coding-teacher.ts`, `shared/coding-teacher.ts`, and `src/pages/Chat/Teacher*.tsx` | Main-owned 云配置、上下文节选/原文读取、本机话题、原生模型只读工具续接、Host API/SSE、独立右侧答疑与运营试聊 | 无 Pi worker 或写入/命令工具；复用 `coding-projects/project-files.ts` 读取当前项目。固定发布版本，账号/项目/来源会话隔离，试聊无真实项目工具。见 [teacher ADR](../10-decisions/ADR-2026-09-22-coding-teacher.md)。 |
 | `electron/coding-projects/project-config.ts`, `src/pages/Chat/CodingProjectConversations.tsx`, and `src/components/layout/Sidebar.tsx` | 内部默认 Agent 与项目下会话导航 | 旧绑定保留；首次发送或显式新建创建会话，打开项目不创建。 |
 | `electron/coding-plugins/manifest.ts`, `release-descriptor.ts`, `signature-verifier.ts`, and `trusted-keys.ts` | Closed Plugin package/descriptor parsing, fixed code-owned resource roots, compatibility checks, canonical archive validation, and Ed25519 trust | Data Service plus exact Game Resource, Game Audio and Project Scaffold roots are code-owned. Other schema-2 packages still pass descriptor/signature/archive validation; downloadable P0 Skill assets remain text/image-only. Hosted Web Search is not a current Plugin root. |
 | `electron/coding-plugins/account-plugin-cache.ts`, `marketplace-client.ts`, and `package-store.ts` | Main-owned Account Library cache, authenticated server client, and atomic immutable device installation store | Account acquisition and device installation are separate. Package bytes switch atomically only after descriptor, signature, archive, client-range, and provenance checks; failed updates preserve the prior current release. |