fix: proširi bilješke na članove tima i osvježi kalendar

Widget Bilješke sada omogućuje odabir više članova tima (ne samo
servisera), a backend validacija i testovi su usklađeni.

Dodatno, nakon realtime service_note notifikacije sada se osvježava
service-notes store, te create flow više ne briše lokalne bilješke kada
odgovor vrati praznu listu.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/modules/fleet/tests/test_service_context_notes.py

@@ -41,6 +41,13 @@ class ServiceContextNotesApiTests(TestCase):
             is_team_member=True,
             is_serviser=True,
         )
+        self.team_member_non_servicer = user_model.objects.create_user(
+            username=f'team-{suffix}',
+            email=f'team-{suffix}@example.test',
+            password='test1234',
+            is_team_member=True,
+            is_serviser=False,
+        )
 
         self.vehicle = Vehicle.objects.create(
             asset_type='crane',
@@ -132,3 +139,31 @@ class ServiceContextNotesApiTests(TestCase):
         )
         self.assertEqual(response.status_code, 201, response.content)
         self.assertEqual(int(response.data.get('created_count', 0)), 2)
+
+    def test_supervisor_can_create_member_note_for_non_servicer_team_member(self):
+        self.client.force_authenticate(user=self.supervisor)
+        response = self.client.post(
+            reverse('service-context-note-list'),
+            data={
+                'note': 'Bilješka za team člana koji nije serviser.',
+                'audience': 'member',
+                'target_users': [str(self.team_member_non_servicer.id)],
+            },
+            format='json',
+        )
+        self.assertEqual(response.status_code, 201, response.content)
+        self.assertEqual(int(response.data.get('created_count', 0)), 1)
+
+    def test_member_note_rejects_non_team_member_target(self):
+        self.client.force_authenticate(user=self.supervisor)
+        response = self.client.post(
+            reverse('service-context-note-list'),
+            data={
+                'note': 'Bilješka ne-smije ići van tima.',
+                'audience': 'member',
+                'target_users': [str(self.other.id)],
+            },
+            format='json',
+        )
+        self.assertEqual(response.status_code, 400, response.content)
+        self.assertIn('target_users', response.data)