fix: create_project auto-add member use role_id

app/api/routers/projects.py

@@ -169,7 +169,8 @@ def create_project(project: schemas.ProjectCreate, db: Session = Depends(get_db)
     db.commit()
     db.refresh(db_project)
     # Auto-add creator as admin member
-    db_member = models.ProjectMember(project_id=db_project.id, user_id=project.owner_id, role="admin")
+    admin_role = db.query(Role).filter(Role.name == "admin").first()
+    db_member = models.ProjectMember(project_id=db_project.id, user_id=project.owner_id, role_id=admin_role.id if admin_role else None)
     db.add(db_member)
     db.commit()
     return db_project