feat: 会议劳务/会务材料分轨审核 + 注册页标题 + 下拉空值修复

会议材料分轨 (material_audit_stage 单轨 → labor/service 双轨):
- biz_meeting: labor_audit_stage/labor_compliance_approved + service_audit_stage/service_compliance_approved 四列替换原单轨两列
- StageDeriver: 单轨状态机(R/N/C0/C1/A) + 角色优先级选代表轨 + 会议物理态取两轨最小进度
- MeetingAuditStageEnum / 前端 meetingStage.js 镜像: 分轨推导 + 颜色跟随角色展示阶段(避免文案与颜色错位)
- BizMeetingController/ServiceImpl/AuditLog + mapper + MeetingStageScheduler 同步分轨字段
- MeetingDetail/Meetings/doctor/executor Meetings/ManagerProjectDetail/ManagerProjectsAssign/PublicityDetail 同步双轨

其它:
- 注册页 (执行单位/专家/支持单位) 加居中页标题
- DoctorDeptSelect/DoctorTitleSelect 空字符串统一 null, 避免挂载必填项飘红
- BizOrgMapper sponsor/executor options 加 status 字段
- sponsor/NewPerson 编辑态 orgName 只读

ry-vue3/src/views/auth/RegisterSponsor.vue

@@ -3,6 +3,8 @@
     <div class="page-wrap">
       <div class="page-card">
 
+      <h2 class="page-title">项目支持单位注册</h2>
+
       <el-steps :active="step" finish-status="success" simple class="steps">
         <el-step title="基本信息" />
         <el-step title="注册成功" />
@@ -210,6 +212,7 @@ onUnmounted(() => { if (smsTimer) clearInterval(smsTimer) })
 
 <style scoped>
 .page-card { max-width: 1200px; margin: 0 auto; }
+.page-title { text-align: center; font-size: 24px; font-weight: 600; color: #303133; margin: 24px 0 0; }
 .steps { max-width: 720px; margin: 24px auto 0; }
 .step-body { max-width: 640px; margin: 32px auto 0; }
 .sms-row { display: flex; gap: 12px; width: 100%; }