新增: Wave8 F-06 导入项目 + F-02 技能联想 + AR-6 Low 失败语义

- F-06 导入历史项目：scan.rs extract_description(README 首段 200 字) + import_project 命令(合并 create+bind，spawn_blocking 探测栈) + 前端 ProjectDetail 导入按钮 + store action；主代理补 lib.rs invoke_handler 注册(agent 未注册)
- F-02 技能联想使用：核对发现 sendMessage→ai_chat_send skill 调用链已完整(联想选中→带 skill→注入 SKILL.md)，补 Esc 取消选中兜底
- AR-6 Low 失败语义统一(定向B)：audit.rs Low 失败 emit AiToolCallCompleted(错误 result) 替代 AiError，消除前端 false/后端 loop 续紊乱，错误回填 tool_result 让 LLM 自处理
cargo/vue-tsc 0 err

src/stores/project.ts

@@ -1,6 +1,7 @@
 import { reactive, computed } from 'vue'
 import { invoke } from '@tauri-apps/api/core'
 import { projectApi, taskApi, ideaApi, workflowApi } from '../api'
+import type { ImportProjectInput } from '../api/project'
 import type { ProjectRecord, TaskRecord, IdeaRecord, WorkflowRecord, WorkflowEventPayload } from '../api/types'
 
 // ── 全局响应式状态（单例） ──
@@ -53,6 +54,18 @@ function createStore() {
     }
   }
 
+  /** 导入历史项目(选已存在目录,后端创建+绑定+探测栈+读 README 首段一步完成) */
+  async function importProject(input: ImportProjectInput) {
+    try {
+      const record = await projectApi.importProject(input)
+      await loadProjects() // 刷新列表(后端已 insert,统一走 load 避免本地数组与后端不一致)
+      return record
+    } catch (e: any) {
+      state.error = e?.toString() ?? '导入项目失败'
+      return null
+    }
+  }
+
   async function updateProject(id: string, field: string, value: string) {
     await projectApi.update(id, field, value)
     const idx = state.projects.findIndex(p => p.id === id)
@@ -298,7 +311,7 @@ function createStore() {
     clearError,
     get deletedProjects() { return state.deletedProjects },
     // project actions
-    loadProjects, createProject, updateProject, deleteProject, relocateProjectPath,
+    loadProjects, createProject, importProject, updateProject, deleteProject, relocateProjectPath,
     loadDeletedProjects, restoreProject, purgeProject,
     // task actions
     loadTasks, createTask, updateTask, deleteTask,