feat(fusion_claims): allow order-less tasks + service-repair SO flag

Relaxes _check_order_link to a no-op (service bookings auto-create their SO;
in-shop/walk-in tasks may have none) and adds x_fc_is_service_repair on
sale.order. The 'Service Repair' crm.tag from the plan is intentionally
omitted: fusion_claims does not depend on crm and sale.order has no tag_ids;
the boolean flag is the repair-SO identity.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

fusion_claims/tests/__init__.py

@@ -4,3 +4,4 @@ from . import test_signed_pages_gate
 from . import test_application_received_wizard
 from . import test_dashboard
 from . import test_service_rate
+from . import test_service_booking

fusion_claims/tests/test_service_booking.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+from datetime import date
+from odoo.tests.common import TransactionCase, tagged
+
+
+@tagged('post_install', '-at_install')
+class TestServiceBooking(TransactionCase):
+
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.Task = cls.env['fusion.technician.task']
+        # technician_id is required on a task (domain x_fc_is_field_staff=True).
+        cls.tech = cls.env['res.users'].create({
+            'name': 'Service Booking Tech',
+            'login': 'svcbook_tech',
+            'x_fc_is_field_staff': True,
+        })
+
+    def test_task_without_order_is_allowed(self):
+        # repair for a brand-new client: no SO/PO must NOT raise after the relax
+        t = self.Task.create({
+            'task_type': 'repair',
+            'technician_id': self.tech.id,
+            'scheduled_date': date(2026, 6, 3),
+        })
+        self.assertTrue(t.id)
+
+    def test_sale_order_has_service_repair_flag(self):
+        so = self.env['sale.order'].new({})
+        self.assertIn('x_fc_is_service_repair', so._fields)