Store Existing Odoo Inventory Field

I need help in Odoo Online (SaaS) to convert an existing custom field (created via Odoo Studio) into a stored database field.

The field name is:

Label Packing (x_label_packing)


It is part of the Product Variants (product.product) model and is already in use — there are several hundred records with existing values.
Currently, the field is not stored=True, which means it cannot be used for sorting or advanced filtering.

I need an experienced Odoo developer to:

correctly make this field stored=True (persisted in the database),

ensure no data is lost,

and make it visible as a sortable field (e.g. in “Sort by” options in Studio).

I’m using Odoo Online (hosted on odoo.com) – no server or shell access, so the work must be done via Studio, Developer Mode, or temporary developer permissions.

✅ Requirements for the Freelancer:

Experience with Odoo Studio (SaaS / Cloud edition)

Knowledge of ir.model.fields and Odoo’s database architecture

Ability to convert Studio-only fields into stored fields without data loss

Familiarity with product.product and product.template models

Confident use of Developer Mode / Debug tools

Access:

I can provide a temporary user account with Studio permissions (not full admin).
Please explain the steps you take so I can replicate them later if needed.

Goal:

After completion, the field x_label_packing should:

appear under Settings → Technical → Database Structure → Fields,

be set to stored=True,

and be available for sorting and filtering in product views (Kanban / List).