Resolve duplicate active user emails

priv/repo/migrations/20260807052500_allow_reusing_deleted_user_emails.exs

@@ -3,6 +3,21 @@ defmodule Claper.Repo.Migrations.AllowReusingDeletedUserEmails do
 
   def change do
     drop_if_exists unique_index(:users, [:email])
+
+    execute """
+    WITH ranked_users AS (
+      SELECT
+        id,
+        ROW_NUMBER() OVER (PARTITION BY email ORDER BY inserted_at, id) AS email_position
+      FROM users
+      WHERE deleted_at IS NULL
+    )
+    UPDATE users
+    SET deleted_at = CURRENT_TIMESTAMP, updated_at = CURRENT_TIMESTAMP
+    FROM ranked_users
+    WHERE users.id = ranked_users.id AND ranked_users.email_position > 1
+    """
+
     create unique_index(:users, [:email], where: "deleted_at IS NULL")
   end
 end