feat(partner): detect and resync partner mismatches on already-imported orders

Detects PF↔PJ transitions and CUI changes after import; auto-resyncs
uninvoiced orders (max 5/cycle) and shows visual alert for invoiced ones.
- SQLite: partner_mismatch column + batch helpers
- sync_service: detection loop + _resync_partner_for_order
- dashboard: red dot + attention card indicator
- modal: alert with contextual message and resync button

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/app/services/order_reader.py

@@ -124,7 +124,9 @@ def _parse_order(order_id: str, data: dict, source_file: str) -> OrderData:
     # Parse billing
     billing_data = data.get("billing", {}) or {}
     company = billing_data.get("company")
-    is_company = isinstance(company, dict) and bool(company.get("name"))
+    is_company = isinstance(company, dict) and (
+        bool(company.get("name")) or bool(company.get("code"))
+    )
 
     billing = OrderBilling(
         firstname=str(billing_data.get("firstname", "")),