Use celery tasks instead of systemd timers for periodic work; and add more tests

chzzk/tasks.py

@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+import logging
+
+from celery import shared_task
+from django.core.management import call_command
+
+logger = logging.getLogger("ttvdrops.tasks")
+
+
+@shared_task(bind=True, queue="imports", max_retries=3, default_retry_delay=60)
+def import_chzzk_campaign_task(self, campaign_no: int) -> None:  # noqa: ANN001
+    """Import a single Chzzk campaign by its campaign number."""
+    try:
+        call_command("import_chzzk_campaign", str(campaign_no))
+    except Exception as exc:
+        raise self.retry(exc=exc) from exc
+
+
+@shared_task(bind=True, queue="api-fetches", max_retries=3, default_retry_delay=120)
+def discover_chzzk_campaigns(self) -> None:  # noqa: ANN001
+    """Discover and import the latest Chzzk campaigns (equivalent to --latest flag)."""
+    try:
+        call_command("import_chzzk_campaign", latest=True)
+    except Exception as exc:
+        raise self.retry(exc=exc) from exc