✨(backend) add admin action to manually retrigger notifications

Enable administrators to manually retrigger external service notifications
from Django admin for failed or missed notification scenarios,
providing operational control over notification delivery.

src/backend/core/admin.py

@@ -1,10 +1,12 @@
 """Admin classes and registrations for core app."""
 
 from django import forms
-from django.contrib import admin
+from django.contrib import admin, messages
 from django.contrib.auth import admin as auth_admin
 from django.utils.translation import gettext_lazy as _
 
+from core.recording.event import notification
+
 from . import models
 
 
@@ -121,6 +123,58 @@ class RecordingAccessInline(admin.TabularInline):
     extra = 0
 
 
+@admin.action(description=_("Resend notification to external service"))
+def resend_notification(modeladmin, request, queryset):  # pylint: disable=unused-argument
+    """Resend notification to external service for selected recordings."""
+
+    notification_service = notification.NotificationService()
+    processed = 0
+    skipped = 0
+    failed = 0
+
+    for recording in queryset:
+        if recording.is_expired:
+            skipped += 1
+            continue
+
+        try:
+            success = notification_service.notify_external_services(recording)
+
+            if success:
+                processed += 1
+            else:
+                failed += 1
+                modeladmin.message_user(
+                    request,
+                    _("Failed to notify for recording %(id)s") % {"id": recording.id},
+                    level=messages.ERROR,
+                )
+
+        except Exception as e:  # noqa: BLE001 # pylint: disable=broad-except
+            failed += 1
+            modeladmin.message_user(
+                request,
+                _("Failed to notify for recording %(id)s: %(error)s")
+                % {"id": recording.id, "error": str(e)},
+                level=messages.ERROR,
+            )
+
+    if processed > 0:
+        modeladmin.message_user(
+            request,
+            _("Successfully sent notifications for %(count)s recording(s).")
+            % {"count": processed},
+            level=messages.SUCCESS,
+        )
+
+    if skipped > 0:
+        modeladmin.message_user(
+            request,
+            _("Skipped %(count)s expired recording(s).") % {"count": skipped},
+            level=messages.WARNING,
+        )
+
+
 @admin.register(models.Recording)
 class RecordingAdmin(admin.ModelAdmin):
     """Recording admin interface declaration."""
@@ -130,6 +184,7 @@ class RecordingAdmin(admin.ModelAdmin):
     list_display = ("id", "status", "room", "get_owner", "created_at", "worker_id")
     list_filter = ["status", "room", "created_at"]
     readonly_fields = ["id", "created_at", "updated_at"]
+    actions = [resend_notification]
 
     def get_queryset(self, request):
         """Optimize queries by prefetching related access and user data to avoid N+1 queries."""