major refactoring adding vendor and customer features

models/database/user.py

@@ -14,6 +14,8 @@ class User(Base, TimestampMixin):
     id = Column(Integer, primary_key=True, index=True)
     email = Column(String, unique=True, index=True, nullable=False)
     username = Column(String, unique=True, index=True, nullable=False)
+    first_name = Column(String)
+    last_name = Column(String)
     hashed_password = Column(String, nullable=False)
     role = Column(String, nullable=False, default="user")  # user, admin, vendor_owner
     is_active = Column(Boolean, default=True, nullable=False)
@@ -23,7 +25,16 @@ class User(Base, TimestampMixin):
     marketplace_import_jobs = relationship(
         "MarketplaceImportJob", back_populates="user"
     )
+
+    # Vendor relationships
     owned_vendors = relationship("Vendor", back_populates="owner")
+    vendor_memberships = relationship("VendorUser", foreign_keys="[VendorUser.user_id]", back_populates="user")
 
     def __repr__(self):
-        return f"<User(username='{self.username}', email='{self.email}', role='{self.role}')>"
+        return f"<User(id={self.id}, username='{self.username}', email='{self.email}', role='{self.role}')>"
+
+    @property
+    def full_name(self):
+        if self.first_name and self.last_name:
+            return f"{self.first_name} {self.last_name}"
+        return self.username