重构: 前端 composable 拆分+详情页 Markdown 渲染+流式 memo+状态同步+bug 修复

- composables/useMarkdown 抽(AiChat 复用)+ai/* 流式核心+useAiSend catch 回滚 user msg(B-21)+useAiStream 超时文案(B-03)+useAiConversations 切换 token(FR-R1)
- views/TaskDetail 新建(F-02)+描述 md+mdReady 响应式+字段同行布局(B-24/31)
- views/ProjectDetail 多选审批 UI(F-01)+描述 md+mdReady+字段同行(B-25/31)
- views/Ideas+Knowledge 描述 md+mdReady(B-25)
- views/Tasks 项目切换联动(B-29)+task 详情跳转
- components/AiChat toast 失败提示(B-20)+流式块级 memo(ARC-08)+clean UI(AR-7)+stop 兜底(AR-5)
- components/ToolCard 审批卡片可读化(AR-3)
- stores useAiStore barrel(ARC-04)+del settings mock(ARC-01)+approve options(R-PD-5)
- i18n aiTool/nav 中英对称(AR-3/9)+删 nav.decisions 死链(ARC-02)
- router /tasks/:id(F-02)+global.css selection 可见(R-260615-01)+api task detail+App 删 decisions nav

src/views/Tasks.vue

@@ -49,7 +49,7 @@
           <span class="group-count">{{ $t('tasks.group.taskCount', { n: group.tasks.length }) }}</span>
         </div>
         <div class="task-list">
-          <div class="task-item" v-for="task in group.tasks" :key="task.id">
+          <div class="task-item" v-for="task in group.tasks" :key="task.id" @click="router.push(`/tasks/${task.id}`)">
             <div class="task-main">
               <div class="task-title-row">
                 <span class="task-title">{{ task.title }}</span>
@@ -101,13 +101,15 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed, onMounted } from 'vue'
+import { ref, computed, onMounted, watch } from 'vue'
+import { useRouter } from 'vue-router'
 import { useI18n } from 'vue-i18n'
 import { useProjectStore } from '../stores/project'
 import { formatRelativeZh } from '../utils/time'
 import { taskStatusLabel as statusLabel, taskStatusClass, priorityLabel, priorityClass } from '../constants/project'
 import type { TaskRecord } from '../api/types'
 
+const router = useRouter()
 const store = useProjectStore()
 const { t } = useI18n()
 
@@ -209,6 +211,11 @@ async function confirmCreate() {
   showCreateModal.value = false
 }
 
+// B-260615-29: 切换项目筛选时按 projectId 重载(避免仅前端 filter,跨项目视图不同步)
+watch(activeProject, (key) => {
+  store.loadTasks(key === 'all' ? undefined : key)
+})
+
 onMounted(async () => {
   await Promise.all([store.loadProjects(), store.loadTasks()])
 })