项目概览、参与者管理初步优化（未接入真实数据）

backend/app/schemas/visit.py

@@ -8,7 +8,6 @@ from pydantic import BaseModel, ConfigDict
 class VisitCreate(BaseModel):
     subject_id: uuid.UUID
     visit_code: str
-    visit_name: str
     planned_date: Optional[date] = None
     window_start: Optional[date] = None
     window_end: Optional[date] = None
@@ -25,7 +24,6 @@ class VisitRead(BaseModel):
     study_id: uuid.UUID
     subject_id: uuid.UUID
     visit_code: str
-    visit_name: str
     planned_date: Optional[date]
     actual_date: Optional[date]
     status: str