项目概览、参与者管理初步优化（未接入真实数据）

backend/app/schemas/subject.py

@@ -9,10 +9,12 @@ class SubjectCreate(BaseModel):
     site_id: uuid.UUID
     subject_no: str
     screening_date: Optional[date] = None
+    consent_date: Optional[date] = None
 
 
 class SubjectUpdate(BaseModel):
     status: Optional[str] = None
+    consent_date: Optional[date] = None
     enrollment_date: Optional[date] = None
     completion_date: Optional[date] = None
     drop_reason: Optional[str] = None
@@ -25,6 +27,7 @@ class SubjectRead(BaseModel):
     subject_no: str
     status: str
     screening_date: Optional[date]
+    consent_date: Optional[date]
     enrollment_date: Optional[date]
     completion_date: Optional[date]
     drop_reason: Optional[str]