Migration to clear invalid custom urls

migrations/20260826153531-clear-invalid-user-custom-urls.ts

@@ -0,0 +1,21 @@
+import { type Kysely, sql } from "kysely";
+
+/**
+ * Clears the custom URLs that predate the `/^[a-zA-Z0-9-_]+$/` rule the profile form
+ * enforces today, leaving those users linked by their Discord id instead.
+ *
+ * They are all from the pre-Kysely era and cannot be created any more, but they are not
+ * harmless leftovers:
+ * - a value containing `?` truncates the link at that character, so `/u/leo?????` is
+ *   requested as `/u/leo` — a 404, or worse, a different user's profile.
+ * - the profile form prefills the field with the stored value, so these users cannot
+ *   save any profile change at all without first picking a new custom URL.
+ */
+export async function up(db: Kysely<any>): Promise<void> {
+	await sql`
+		update "User"
+		set "customUrl" = null
+		where "customUrl" is not null
+			and "customUrl" glob '*[^a-zA-Z0-9_-]*'
+	`.execute(db);
+}