feat: init

migrate/004_auth_constraints.sql

@@ -0,0 +1,8 @@
+-- Auth identity uniqueness and lookup hardening.
+CREATE UNIQUE INDEX IF NOT EXISTS uq_user_username_active_ci
+    ON "user" (lower(username))
+    WHERE deleted_at IS NULL;
+
+CREATE UNIQUE INDEX IF NOT EXISTS uq_user_mail_verified_email_ci
+    ON user_mail (lower(email))
+    WHERE is_verified = true;