feat(core): add core module with mixins, services, and background jobs

- Add Model Mixins: TimestampMixin, SoftDeleteMixin, AuditMixin, etc.
- Add Base Services: BaseService, BulkOperationsMixin, QueryOptimizerMixin
- Add Base ViewSets with bulk operations
- Add BackgroundJob model for Celery task tracking
- Add BaseAppCommand for management commands
- Add permissions, pagination, filters, cache, logging
- Migrate tests to factory_boy + faker
- Add CHANGELOG.md
- 297 tests passing

src/config/api_v1_urls.py

@@ -0,0 +1,20 @@
+"""
+API v1 URL configuration.
+
+All API endpoints are versioned under /api/v1/
+"""
+
+from apps.core.views import BackgroundJobListView, BackgroundJobStatusView
+from django.urls import include, path
+
+app_name = "api_v1"
+
+jobs_urlpatterns = [
+    path("", BackgroundJobListView.as_view(), name="job-list"),
+    path("<str:task_id>/", BackgroundJobStatusView.as_view(), name="job-status"),
+]
+
+urlpatterns = [
+    path("users/", include("apps.user.urls")),
+    path("jobs/", include((jobs_urlpatterns, "jobs"))),
+]