fix(server): info toast on bulk_update with no matching ids

Seventh Copilot pass on #3048: assets_bulk_update returned a silent
no-toast 2xx when the posted ids matched no rows (stale selection), so
the client's success gate cleared the selection / closed the modal
even though nothing applied. Return the same info toast the
enable/disable path uses so the selection is kept. Adds a test.

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

Author: vpetersson

src/anthias_server/app/views.py

@@ -804,7 +804,15 @@ def assets_bulk_update(request: HttpRequest) -> HttpResponse:
         return _asset_table_response(request)
     assets = list(Asset.objects.filter(asset_id__in=ids))
     if not assets:
-        return _asset_table_response(request)
+        # Non-empty ids that match nothing (e.g. a stale selection after
+        # another operator deleted the rows). Toast so the client's
+        # success gate keeps the selection / leaves the modal open
+        # rather than treating a silent no-toast 2xx as success — same
+        # contract as the enable/disable path.
+        return _asset_table_response(
+            request,
+            toast=('info', 'No matching assets selected'),
+        )
 
     apply_dates = request.POST.get('apply_dates') == 'true'
     apply_duration = request.POST.get('apply_duration') == 'true'

tests/test_template_views.py

@@ -1191,6 +1191,32 @@ def test_assets_bulk_action_no_matching_ids_keeps_selection(
     assert trigger['toast']['kind'] == 'info'
 
 
+@pytest.mark.django_db
+def test_assets_bulk_update_unmatched_ids_keeps_selection(
+    client: Client, bulk_assets: list[Asset]
+) -> None:
+    """bulk_update with non-empty but unmatched ids returns an info
+    toast (not a silent no-toast 2xx) so the client keeps the selection
+    and the modal stays open (Copilot review of #3048)."""
+    import json as _json
+
+    with mock.patch(
+        'anthias_server.settings.ViewerPublisher.send_to_viewer',
+        return_value=None,
+    ):
+        response = client.post(
+            reverse('anthias_app:assets_bulk_update'),
+            data={
+                'ids': 'no-such-id,also-missing',
+                'apply_duration': 'true',
+                'duration': '42',
+            },
+            HTTP_HX_REQUEST='true',
+        )
+    trigger = _json.loads(response['HX-Trigger'])
+    assert trigger['toast']['kind'] == 'info'
+
+
 @pytest.mark.django_db
 def test_assets_bulk_update_dates(
     client: Client, bulk_assets: list[Asset]