docs(design): 搜索 Agent 装配层设计（app/search/）

方案 A 平铺模块：prompt.py / skills.py / tools.py / vision.py
新增 OCRProvider Protocol + adapters/ocr.py
Prompt 从 TRM4 store/prompts/v2/ 原封不动复制

research-wiki/index.md

@@ -1,15 +1,19 @@
 # Research Wiki 索引
 
-> 自动生成，更新时间：2026-07-07 05:27 UTC
+> 自动生成，更新时间：2026-07-07 09:14 UTC
 
-## design (3)
+## design (5)
 - [2026-07-06-core-agent-adapters-llm-design](designs/2026-07-06-core-agent-adapters-llm-design.md) `design:2026-07-06-core-agent-adapters-llm-design`
+- [出题模块迁移设计（question_gen）](designs/2026-07-07-question-gen-design.md) `design:2026-07-07-question-gen-design`
 - [建树模块竖切设计：数据结构 + 建树 + 修复 + 迁移](designs/2026-07-07-tree-module-design.md) `design:2026-07-07-tree-module-design`
 - [建树模块竖切设计：数据结构 + 建树 + 修复 + 迁移](designs/tree-module-vertical-slice.md) `design:tree-module-vertical-slice`
+- [搜索 Agent 装配层设计（app/search/）](designs/2026-07-07-search-module-design.md) `design:2026-07-07-search-module-design`
 
-## plan (5)
+## plan (7)
 - [2026-07-06-core-agent-adapters-llm](plans/2026-07-06-core-agent-adapters-llm.md) `plan:2026-07-06-core-agent-adapters-llm`
+- [2026-07-07-question-gen](plans/2026-07-07-question-gen.md) `plan:2026-07-07-question-gen`
 - [2026-07-07-tree-module-vertical-slice](plans/2026-07-07-tree-module-vertical-slice.md) `plan:2026-07-07-tree-module-vertical-slice`
 - [core/agent/ + adapters/llm 基础设施实现计划](plans/core-agent-adapters-llm.md) `plan:core-agent-adapters-llm`
+- [question_gen 模块实现计划](plans/question-gen.md) `plan:question-gen`
 - [建树模块竖切实现计划](plans/tree-module-vertical-slice.md) `plan:tree-module-vertical-slice`
 - [项目基础设施初始化计划](plans/infrastructure-setup.md) `plan:infrastructure-setup`