Initial public commit

Daybook: a self-hosted, multi-user Django + DRF app where agents, scripts,
or people publish artifacts and each logged-in user browses their own
time-ordered, label-filterable feed.

This squashes prior local development history (kept privately on a separate
branch) into a single clean starting point for the public repository.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

artifacts/migrations/0006_backfill_owner.py

@@ -0,0 +1,27 @@
+from django.db import migrations
+
+
+def backfill_owner(apps, schema_editor):
+    User = apps.get_model("auth", "User")
+    Artifact = apps.get_model("artifacts", "Artifact")
+
+    first_superuser = User.objects.filter(is_superuser=True).order_by("date_joined").first()
+    if first_superuser is None:
+        return
+
+    Artifact.objects.filter(owner__isnull=True).update(owner=first_superuser)
+
+
+def noop_reverse(apps, schema_editor):
+    pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("artifacts", "0005_add_owner_nullable"),
+    ]
+
+    operations = [
+        migrations.RunPython(backfill_owner, noop_reverse),
+    ]