feat: account deletion request and active-user check

crates/adapters/sqlite/src/repositories/users/mod.rs

@@ -171,7 +171,7 @@ impl UserRepository for SqliteUserRepository {
             .map_err(crate::shared::map_sqlx_error)?;
         let stamped =
             sqlx::query("UPDATE users SET deleted_at = ? WHERE id = ? AND deleted_at IS NULL")
-                .bind(Utc::now().to_rfc3339())
+                .bind(Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string())
                 .bind(&id_str)
                 .execute(&mut *tx)
                 .await