Add better email verification

apps/submissions/migrations/0004_email_normalization.py

@@ -0,0 +1,51 @@
+"""Schema changes for the email normalisation / TTL / cap work.
+
+- `Submission.canonical_email`: new indexed column populated by
+  `Submission.save()`. Used to count active submissions per email for the
+  10-cap, and to look up the `VerifiedEmail` trust list.
+- `VerifiedEmail.verified_at` -> `validated_at`: keeps the data, drops the
+  `auto_now_add` so `update_or_create` can roll the timestamp forward on
+  every re-confirmation (rolling 30-day TTL).
+- `VerifiedEmail.updated_at`: removed -- `validated_at` IS the most recent
+  confirmation timestamp now, no need for a second column.
+
+The data backfill (populate canonical_email, re-normalise existing
+VerifiedEmail rows) lives in 0005_normalize_existing_data so this
+migration stays a clean schema-only change.
+"""
+
+import django.utils.timezone
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("submissions", "0003_backfill_verified_emails"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="submission",
+            name="canonical_email",
+            field=models.EmailField(blank=True, db_index=True, max_length=254),
+        ),
+        migrations.RenameField(
+            model_name="verifiedemail",
+            old_name="verified_at",
+            new_name="validated_at",
+        ),
+        migrations.RemoveField(
+            model_name="verifiedemail",
+            name="updated_at",
+        ),
+        migrations.AlterField(
+            model_name="verifiedemail",
+            name="validated_at",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+        migrations.AlterModelOptions(
+            name="verifiedemail",
+            options={"ordering": ("-validated_at",)},
+        ),
+    ]