feat: implement order sync lifecycle (WC→Odoo SO/invoice, shipping push, completion push)

- Replace _sync_orders placeholder with full WC order import pipeline
- Add _sync_order_from_wc, _find_or_create_customer, _prepare_sale_order_vals,
  _prepare_order_line_vals, _prepare_shipping_line_vals helpers
- Add push methods on woo.order: action_push_shipping, action_push_completed,
  action_push_invoice_pdf, action_push_delivery_pdf, _push_messages_to_wc
- Override stock.picking button_validate to auto-create shipment records and
  push tracking/delivery PDFs to WooCommerce

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

fusion-woo-odoo/fusion_woocommerce/models/stock_picking.py

@@ -1,5 +1,9 @@
+import logging
+
 from odoo import models, fields
 
+_logger = logging.getLogger(__name__)
+
 
 class StockPicking(models.Model):
     _inherit = 'stock.picking'
@@ -14,3 +18,40 @@ class StockPicking(models.Model):
             picking.is_woo_delivery = bool(picking.woo_shipment_ids) or bool(
                 picking.sale_id and picking.sale_id.woo_bind_ids
             )
+
+    def button_validate(self):
+        """Override to auto-create shipment and push tracking to WC."""
+        res = super().button_validate()
+        for picking in self:
+            if not picking.sale_id or not picking.sale_id.woo_bind_ids:
+                continue
+            woo_order = picking.sale_id.woo_bind_ids[0]
+            # Create shipment record
+            shipment_vals = {
+                'order_id': woo_order.id,
+                'picking_id': picking.id,
+                'carrier_id': picking.woo_carrier_id.id if picking.woo_carrier_id else False,
+                'tracking_number': picking.woo_tracking_number or '',
+                'shipped_date': fields.Datetime.now(),
+                'is_backorder': bool(picking.backorder_ids),
+                'company_id': picking.company_id.id,
+            }
+            shipment = self.env['woo.shipment'].create(shipment_vals)
+
+            # Auto-push to WC if tracking number is set
+            if picking.woo_tracking_number:
+                try:
+                    woo_order.action_push_shipping(
+                        picking.woo_tracking_number,
+                        picking.woo_carrier_id.id if picking.woo_carrier_id else False,
+                    )
+                    shipment.synced_to_woo = True
+                except Exception as e:
+                    _logger.error("Failed to push shipping to WC: %s", e)
+
+            # Push delivery PDF
+            try:
+                woo_order.action_push_delivery_pdf(picking)
+            except Exception as e:
+                _logger.warning("Failed to push delivery PDF to WC: %s", e)
+        return res