refactor(projects): 项目分配 dialog 拆为独立子页面

- 新增 ManagerProjectsAssign.vue (单条/批量共用, 通过 route.query.projectId/projectIds 区分)
- router 加 2 个路由 /manager/projects/assign 和 /assign-batch
- Projects.vue 移除项目分配 dialog (template + 9 个 state/computed/function)
- Projects.vue 两个入口 (toolbar 项目分配 + 行内项目分配) 改为 router.push
- 顶部筛选区的 searchSponsorOrgsForFilter / searchExecutorOrgsForFilter 保留 (跟子页面解耦)
- 功能 1:1 不变: 支持方 / 实时校验 / 执行方分配 / 总场次超量校验 / 提交截止天数

Co-Authored-By: Claude <noreply@anthropic.com>

ry-vue3/src/router/index.js

@@ -61,6 +61,8 @@ const routes = [
       { path: 'projects/new', name: 'manager-projects-new', component: () => import('@/views/manager/ProjectsNew.vue'), meta: { title: '新建项目' } },
       { path: 'projects/edit/:projectId', name: 'manager-projects-edit', component: () => import('@/views/manager/ProjectsNew.vue'), meta: { title: '编辑项目' } },
       { path: 'projects/detail/:projectId', name: 'manager-projects-detail', component: () => import('@/views/manager/ManagerProjectDetail.vue'), meta: { title: '项目详情' } },
+      { path: 'projects/assign', name: 'manager-projects-assign', component: () => import('@/views/manager/ManagerProjectsAssign.vue'), meta: { title: '项目分配' } },
+      { path: 'projects/assign-batch', name: 'manager-projects-assign-batch', component: () => import('@/views/manager/ManagerProjectsAssign.vue'), meta: { title: '批量项目分配' } },
       { path: 'meetings', name: 'manager-meetings', component: () => import('@/views/manager/Meetings.vue'), meta: { title: '会议管理' } },
       { path: 'meetings/new', name: 'manager-meetings-new', component: () => import('@/views/manager/MeetingNew.vue'), meta: { title: '新建会议' } },
       { path: 'experts', name: 'manager-experts', component: () => import('@/views/expert/Experts.vue'), meta: { title: '专家审核' } },