db: drop legacy key fields in users table

lib/pleroma/user.ex

@@ -100,7 +100,6 @@ defmodule Pleroma.User do
     field(:password_hash, :string)
     field(:password, :string, virtual: true)
     field(:password_confirmation, :string, virtual: true)
-    field(:keys, :string)
     field(:ap_id, :string)
     field(:avatar, :map, default: %{})
     field(:local, :boolean, default: true)

priv/repo/migrations/20240625220752_move_signing_keys.exs

@@ -11,7 +11,7 @@ def up do
     # Also this MUST use select, else the migration will fail in future installs with new user fields!
     from(u in Pleroma.User,
       where: u.local == true,
-      select: {u.id, u.keys, u.ap_id}
+      select: {u.id, fragment("?.keys", u), u.ap_id}
     )
     |> Repo.stream(timeout: :infinity)
     |> Enum.each(fn

priv/repo/migrations/20250112000002_users_drop_legacy_key_fields.exs

@@ -0,0 +1,31 @@
+defmodule Pleroma.Repo.Migrations.UsersDropLegacyKeyFields do
+  use Ecto.Migration
+
+  def up() do
+    alter table(:users) do
+      remove :keys, :text
+      remove :public_key, :text
+    end
+  end
+
+  def down() do
+    # Using raw query since the "keys" field may not exist in the Elixir Ecto schema
+    # causing issues when migrating data back and this requires column adds to be raw query too
+    """
+    ALTER TABLE public.users
+    ADD COLUMN keys text,
+    ADD COLUMN public_key text;
+    """
+    |> Pleroma.Repo.query!([], timeout: :infinity)
+
+    """
+    UPDATE public.users AS u
+    SET keys = s.private_key
+    FROM public.signing_keys AS s
+    WHERE s.user_id = u.id AND
+          u.local AND
+          s.private_key IS NOT NULL;
+    """
+    |> Pleroma.Repo.query!([], timeout: :infinity)
+  end
+end

test/pleroma/user_test.exs

@@ -1708,7 +1708,6 @@ test "delete/1 purges a user when they wouldn't be fully deleted" do
         bio: "eyy lmao",
         name: "qqqqqqq",
         password_hash: "pdfk2$1b3n159001",
-        keys: "RSA begin buplic key",
         avatar: %{"a" => "b"},
         tags: ["qqqqq"],
         banner: %{"a" => "b"},