feat: add communication history push, invoice auto-trigger, health checks, rate limiting

- Override account.move action_post to auto-push invoice PDF to WC on posting
- Add _cron_health_check to ping all instances and flag unreachable ones
- Add health check cron record (every 10 minutes) to data/cron.xml
- Add IP-based rate limiting (100 req/min) to webhook controller
- Fill in API endpoints: order/documents, order/status, order/messages
  with real data from woo.order, stock.picking, and mail.message
- Implement return/create API endpoint with product mapping and line creation

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

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

@@ -1,5 +1,9 @@
+import logging
+
 from odoo import models, fields
 
+_logger = logging.getLogger(__name__)
+
 
 class AccountMove(models.Model):
     _inherit = 'account.move'
@@ -10,3 +14,15 @@ class AccountMove(models.Model):
     def _compute_is_woo_invoice(self):
         for move in self:
             move.is_woo_invoice = bool(move.woo_order_id)
+
+    def action_post(self):
+        """Override to auto-push invoice PDF to WooCommerce on posting."""
+        res = super().action_post()
+        for move in self:
+            if move.woo_order_id and not move.woo_order_id.invoice_synced:
+                try:
+                    move.woo_order_id.action_push_invoice_pdf()
+                    move.woo_order_id.invoice_synced = True
+                except Exception as e:
+                    _logger.error("Failed to push invoice PDF to WC: %s", e)
+        return res