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/0007_owner_required.py

@@ -0,0 +1,23 @@
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ("artifacts", "0006_backfill_owner"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="artifact",
+            name="owner",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="artifacts",
+                to=settings.AUTH_USER_MODEL,
+            ),
+        ),
+    ]