feat(configurator): drop legacy description column after dual-field migration (Sub 2 Task 27)

Removes the `description` field from `fp.sale.description.template` now
that all readers (reports, wizard, sale line) consume the new
`internal_description` + `customer_facing_description` pair.

- Model: drop `description = fields.Text(...)` declaration
- Migration 19.0.9.0.0 Step 6: `ALTER TABLE ... DROP COLUMN IF EXISTS description`
- Template form/search views: swap `description` for the two new fields
- Seed data: write new fields instead of legacy column (dupes old text into both)
- Direct-order wizard: remove `tpl.description` fallback in both onchange handlers

Entech column dropped via Odoo's auto-schema-sync during module upgrade
(migration step is for fresh installs).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_configurator/views/fp_sale_description_template_views.xml

@@ -54,8 +54,12 @@
                             <field name="active" widget="boolean_toggle"/>
                         </group>
                     </group>
-                    <group string="Description">
-                        <field name="description" nolabel="1" colspan="2"
+                    <group string="Internal Description (Shop Floor Only)">
+                        <field name="internal_description" nolabel="1" colspan="2"
+                               placeholder="What the shop floor sees on the WO / traveler…"/>
+                    </group>
+                    <group string="Customer-Facing Description">
+                        <field name="customer_facing_description" nolabel="1" colspan="2"
                                placeholder="Electroless nickel plating per AMS 2404, Class I, Type II…"/>
                     </group>
                 </sheet>
@@ -69,7 +73,8 @@
         <field name="arch" type="xml">
             <search>
                 <field name="name"/>
-                <field name="description"/>
+                <field name="internal_description"/>
+                <field name="customer_facing_description"/>
                 <field name="part_catalog_id"/>
                 <field name="coating_config_id"/>
                 <field name="partner_id"/>