docs(architecture): update impact map, data, troubleshooting, add mockups

- Update 004_architecture_impact_map.md and 005_architecture_data.json

- Remove obsolete _update_004.cjs helper script

- Update troubleshooting/known-issues.md

- Add docs/mockups/ directory

docs/architecture/005_architecture_data.json

@@ -6713,7 +6713,11 @@
         ],
         "uiDeps": [],
         "uiDepsNote": "已通过 render prop 解耦，TeacherTextbookReader 已移至 app 层（src/app/(dashboard)/teacher/textbooks/[id]/_components/），textbooks 模块不再直接 import questions 模块组件",
-        "npmDeps": ["@xyflow/react", "@dagrejs/dagre", "react-force-graph-2d"],
+        "npmDeps": [
+          "@xyflow/react",
+          "@dagrejs/dagre",
+          "react-force-graph-2d"
+        ],
         "npmDepsNote": "v4 新增 react-force-graph-2d（基于 d3-force + Canvas）实现 Obsidian 风格力导向图谱；通过 next/dynamic ssr:false 加载避免 SSR canvas/window 报错；@xyflow/react + @dagrejs/dagre 用于分层有向图布局",
         "knownIssues": [
           "v4 新增（2026-07-03）：知识点图谱新增 Obsidian 风格力导向布局（force 模式），与原分层有向图（hierarchical 模式）共存，工具栏可切换；新增组件 force-graph.tsx，新增类型 GraphLayoutMode；保留全部现有功能（掌握度视图/搜索高亮/邻居高亮/前置依赖增删）",
@@ -20777,6 +20781,30 @@
             "permission": "LESSON_PLAN_READ",
             "file": "actions-ai.ts",
             "purpose": "V5-21 A4 辅助新增：按 textbookId 获取知识点列表（仅 id+name），供课标核对 Tab 按需加载"
+          },
+          {
+            "name": "generateNodeContentAction",
+            "permission": "LESSON_PLAN_READ + LESSON_PLAN_CREATE + AI_CHAT",
+            "file": "actions-ai.ts",
+            "purpose": "V4-N1 新增：节点级 AI 协助 - 根据节点 type 生成对应字段，返回 patch 由前端合并到 node.data"
+          },
+          {
+            "name": "optimizeNodeExpressionAction",
+            "permission": "LESSON_PLAN_READ + LESSON_PLAN_CREATE + AI_CHAT",
+            "file": "actions-ai.ts",
+            "purpose": "V4-N2 新增：节点级 AI 协助 - 优化节点现有表达，保留结构仅修改字段值"
+          },
+          {
+            "name": "suggestNodeDifferentiationAction",
+            "permission": "LESSON_PLAN_READ + LESSON_PLAN_CREATE + AI_CHAT",
+            "file": "actions-ai.ts",
+            "purpose": "V4-N3 新增：节点级 AI 协助 - 判定节点适合的差异化层次（basic/intermediate/advanced），前端据此设置 node.differentiation"
+          },
+          {
+            "name": "generateLayeredQuestionsAction",
+            "permission": "LESSON_PLAN_READ + LESSON_PLAN_CREATE + AI_CHAT",
+            "file": "actions-ai.ts",
+            "purpose": "V4-N4 新增：节点级 AI 协助 - 为 interaction 节点生成分层提问，返回 QATurn[] 由前端追加到 turns"
           }
         ],
         "schemas": [
@@ -20876,6 +20904,7 @@
         "lib/document-migration.ts",
         "lib/node-summary.ts",
         "lib/anchor-mark.ts",
+        "lib/ai-node-assist.ts",
         "lib/export.ts",
         "lib/scope-check.ts",
         "lib/document-diff.ts",
@@ -20903,6 +20932,7 @@
         "hooks/version-slice.ts",
         "hooks/history-slice.ts",
         "hooks/expanded-slice.ts",
+        "hooks/use-node-ai-assist.ts",
         "components/lesson-plan-list.tsx",
         "components/lesson-plan-card.tsx",
         "components/lesson-plan-filters.tsx",
@@ -21059,7 +21089,10 @@
         "V4-PAPER-6": "J3 lint + tsc 零错误验证：tsc --noEmit 0 错误；lint 中 V4 引入的 react-hooks/set-state-in-effect 错误已通过 anchor-migration-banner.tsx 的 key-based remount + lazy initial state 模式修复；剩余 6 个 lint 错误为预存无关模块问题（exams/use-exam-preview-tasks react-hooks/refs 3 个、template-picker V5-9 set-state-in-effect 1 个），按计划要求记录不修复",
         "V4-PAPER-7": "J4 架构图同步：004_architecture_impact_map.md 新增 V4 纸感重构章节；005_architecture_data.json 更新 lesson_preparation 节点——description 改为 V4 描述、dependencies 移除 @xyflow/react 改为 @tiptap/* 包、files 数组移除 9 个废弃文件并新增 V4 组件（paper-editor/structure-tree/detail-panel/interaction-block/anchor-migration-banner/print-view/schedule-dialog/consistency-check-dialog/ai-feedback-dialog/ai-differentiation-dialog/expanded-slice/history-slice/anchor-mark/export/scope-check/document-diff 等）、auditFixes 新增 V4-PAPER-1~7 条目",
         "V4-PAPER-8": "J5 known-issues V4 规则：docs/troubleshooting/known-issues.md 新增 V4 纸感重构规则表，记录 8 条规则——React Flow 弃用、Tiptap Mark 锚点替代字符串偏移、setState in effect 禁用（用 key-based remount + lazy initial state 替代）、doc.version=4、editor-slice 移除画布相关方法、interaction block 注册、PrintView 按 order 排序、AnchorMigrationBanner 失效提示",
-        "V4-PAPER-DOC": "documentVersion 升级为 4：types.ts LessonPlanDocument.version = 4；lib/document-migration.ts normalizeDocument 兼容 v1/v2/v3/v4 链式迁移；editor-slice.ts 移除 updateNodePosition/connect/setEdges/autoLayout 画布相关方法；hooks/expanded-slice.ts 新增 expandedNodeIds/toggleExpand/setExpanded 状态（节点展开到正文流）；lib/anchor-mark.ts 新增 Tiptap AnchorMark + AnchorPoint 扩展（替代 v3 字符串偏移锚点）"
+        "V4-PAPER-DOC": "documentVersion 升级为 4：types.ts LessonPlanDocument.version = 4；lib/document-migration.ts normalizeDocument 兼容 v1/v2/v3/v4 链式迁移；editor-slice.ts 移除 updateNodePosition/connect/setEdges/autoLayout 画布相关方法；hooks/expanded-slice.ts 新增 expandedNodeIds/toggleExpand/setExpanded 状态（节点展开到正文流）；lib/anchor-mark.ts 新增 Tiptap AnchorMark + AnchorPoint 扩展（替代 v3 字符串偏移锚点）",
+        "V4-PAPER-V2-1": "V2 复制节点功能完整实现：hooks/editor-slice.ts 新增 duplicateNode(id) 方法（深拷贝 BlockData + 新 id + 标题加'副本' + order 置末，interaction 节点的 turns 重新生成 id 避免冲突）；components/paper-editor/paper-context-menu.tsx 的 copyNode 从 toast 占位改为调用 duplicateNode 并 toast 成功提示；i18n 新增 v4.contextMenu.copied/copyFailed 键（zh-CN + en）",
+        "V4-PAPER-V2-2": "V2 节点级 AI 协助 4 项完整实现：lib/ai-node-assist.ts 新增 4 个服务函数（generateNodeContent/optimizeNodeExpression/suggestNodeDifferentiation/generateLayeredQuestions），全部纯服务端、Zod 校验、失败返回 null；actions-ai.ts 新增 4 个 Server Action，每个 action 校验 LESSON_PLAN_READ + LESSON_PLAN_CREATE + AI_CHAT 三个权限点；hooks/use-node-ai-assist.ts 新增客户端 hook；components/paper-editor/paper-editor.tsx 注入 onAiAction 回调；components/detail-panel/detail-panel.tsx 的 4 个 AiButton 接入真实 action；i18n 新增 v4.contextMenu.aiRunning/aiSuccess/aiFailed/aiComingSoon 键",
+        "V4-I18N-1": "i18n 完整审查与修复：P0 修复 version.diff.* 3 键 + schema.ts 8 个 error.* 键 + contextMenu 6 键（zh-CN + en 同步）；P1 修复 en calendar 节键名对齐 zh-CN；P2 修复 7 处硬编码中文 + 新增 6 个 i18n 键；清理 7 个 dead 节（review/comment/formative/substitute/evaluation/standards/gradeHead，analytics 因被 admin/curriculum-map 引用保留）；lib/i18n-errors.ts 新增 t.has() 守卫"
       }
     },
     "error-book": {
@@ -26907,4 +26940,4 @@
       }
     }
   }
-}
+}