[REF] product_origin_char: simplify to template-based origin

- Move origin_text field from product.supplierinfo to product.template
- Add related field in product.product for variant access
- Remove dependency on product_main_seller
- Update views to show field near category (editable)
- Rewrite tests for new architecture
- Update all documentation (README, readme/ fragments)
- Bump version to 18.0.2.0.0

product_origin_char/models/product_product.py

@@ -1,7 +1,6 @@
 # Copyright 2026 Criptomart
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
-from odoo import api
 from odoo import fields
 from odoo import models
 
@@ -10,21 +9,6 @@ class ProductProduct(models.Model):
     _inherit = "product.product"
 
     origin_text = fields.Char(
-        string="Origin",
-        compute="_compute_origin_text",
-        store=False,
-        help="Origin text from main vendor's supplierinfo",
+        related="product_tmpl_id.origin_text",
+        readonly=False,
     )
-
-    @api.depends("product_tmpl_id.main_seller_id", "seller_ids.origin_text")
-    def _compute_origin_text(self):
-        for product in self:
-            if product.product_tmpl_id.main_seller_id:
-                # Find the supplierinfo record for the main seller
-                main_seller = product.product_tmpl_id.main_seller_id
-                seller = product.seller_ids.filtered(
-                    lambda s, ms=main_seller: s.partner_id == ms
-                )[:1]
-                product.origin_text = seller.origin_text if seller else False
-            else:
-                product.origin_text = False