refactor: remove Vendor.owner_user_id column

- Remove owner_user_id column and owner relationship from Vendor model
- Update User model ownership checks to use company relationship
- Add migration to drop owner_user_id column from vendors table

Ownership is now determined solely via vendor.company.owner_user_id

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

models/database/user.py

@@ -51,7 +51,6 @@ class User(Base, TimestampMixin):
         "MarketplaceImportJob", back_populates="user"
     )
     owned_companies = relationship("Company", back_populates="owner")
-    owned_vendors = relationship("Vendor", back_populates="owner")
     vendor_memberships = relationship(
         "VendorUser", foreign_keys="[VendorUser.user_id]", back_populates="user"
     )
@@ -78,12 +77,20 @@ class User(Base, TimestampMixin):
         return self.role == UserRole.VENDOR.value
 
     def is_owner_of(self, vendor_id: int) -> bool:
-        """Check if user is the owner of a specific vendor."""
-        return any(v.id == vendor_id for v in self.owned_vendors)
+        """
+        Check if user is the owner of a specific vendor.
+
+        Ownership is determined via company ownership:
+        User owns Company → Company has Vendor → User owns Vendor
+        """
+        for company in self.owned_companies:
+            if any(v.id == vendor_id for v in company.vendors):
+                return True
+        return False
 
     def is_member_of(self, vendor_id: int) -> bool:
         """Check if user is a member of a specific vendor (owner or team)."""
-        # Check if owner
+        # Check if owner (via company)
         if self.is_owner_of(vendor_id):
             return True
         # Check if team member
@@ -93,7 +100,7 @@ class User(Base, TimestampMixin):
 
     def get_vendor_role(self, vendor_id: int) -> str:
         """Get user's role within a specific vendor."""
-        # Check if owner
+        # Check if owner (via company)
         if self.is_owner_of(vendor_id):
             return "owner"
 

models/database/vendor.py

@@ -50,10 +50,6 @@ class Vendor(Base, TimestampMixin):
     name = Column(String, nullable=False)  # Non-nullable name column for the vendor (brand name)
     description = Column(Text)  # Optional text description column for the vendor
 
-    owner_user_id = Column(
-        Integer, ForeignKey("users.id"), nullable=True
-    )  # Foreign key to user ID of the vendor's owner (DEPRECATED - use company.owner_user_id instead)
-
     # Letzshop URLs - multi-language support (brand-specific marketplace feeds)
     letzshop_csv_url_fr = Column(String)  # URL for French CSV in Letzshop
     letzshop_csv_url_en = Column(String)  # URL for English CSV in Letzshop
@@ -73,9 +69,6 @@ class Vendor(Base, TimestampMixin):
     company = relationship(
         "Company", back_populates="vendors"
     )  # Relationship with Company model for the parent company
-    owner = relationship(
-        "User", back_populates="owned_vendors"
-    )  # Relationship with User model for the vendor's owner (legacy)
     vendor_users = relationship(
         "VendorUser", back_populates="vendor"
     )  # Relationship with VendorUser model for users in this vendor