feat: push variants button on mapped products — convert simple→variable in WC

When a mapped product is simple on WC but has variants in Odoo, a purple
"N variants" button appears in the Variants column. Clicking it:
1. Converts the WC product from simple to variable
2. Creates WC attributes and terms from Odoo attribute lines
3. Creates a WC variation for each Odoo variant with price/SKU/stock/tax/image
4. Creates woo.product.map records for each variation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fusion-woo-odoo/fusion_woocommerce/static/src/js/product_mapping.js

@@ -855,6 +855,29 @@ export class ProductMapping extends Component {
         }
     }
 
+    // -------------------------------------------------------------------------
+    // Push variants to WC
+    // -------------------------------------------------------------------------
+
+    async pushVariantsToWC(mapId) {
+        try {
+            this.state.loading = true;
+            await rpc("/web/dataset/call_kw", {
+                model: "woo.product.map",
+                method: "action_push_variants_to_wc",
+                args: [[mapId]],
+                kwargs: {},
+            });
+            this.notification.add("Variants pushed to WooCommerce successfully.", { type: "success" });
+            await this._refreshAll();
+        } catch (err) {
+            console.error("[ProductMapping] pushVariantsToWC error:", err);
+            this.notification.add(err.message || "Failed to push variants.", { type: "danger" });
+        } finally {
+            this.state.loading = false;
+        }
+    }
+
     // -------------------------------------------------------------------------
     // Bulk price sync
     // -------------------------------------------------------------------------