Set per-outlet modifier option override

Set a per-outlet override for a modifier option on an item in a section. Supports disabling the option and/or overriding the additional price per order type. When this override exists, it is written to the live per-outlet modifier option table during publish. **Price overrides:** Each order type (base, eat-in, delivery) can have an independent price override. Pass `null` or omit a price field to clear that override (falls back to the catalog price). Pass `0` to explicitly set a zero surcharge. **Publish behavior:** Overrides are written to the live modifier option availability table. Options without overrides remain enabled with catalog prices by default.