feat(system_actor): add system_user?/1 and normalize email

Case-insensitive email comparison for system-actor detection.

lib/mv/helpers/system_actor.ex

@@ -172,6 +172,31 @@ defmodule Mv.Helpers.SystemActor do
     end
   end
 
+  @doc """
+  Returns whether the given user is the system actor user (case-insensitive email match).
+
+  Use this instead of ad-hoc `to_string(user.email) == system_user_email()` so
+  comparisons are consistent and case-insensitive everywhere.
+
+  ## Returns
+
+  - `boolean()` - true if user's email matches system user email (case-insensitive)
+
+  ## Examples
+
+      iex> Mv.Helpers.SystemActor.system_user?(user_with_system_email)
+      true
+      iex> Mv.Helpers.SystemActor.system_user?(other_user)
+      false
+
+  """
+  @spec system_user?(Mv.Accounts.User.t() | map() | nil) :: boolean()
+  def system_user?(%{email: email}) when not is_nil(email) do
+    normalized_email(to_string(email)) == normalized_system_user_email()
+  end
+
+  def system_user?(_), do: false
+
   @doc """
   Returns the email address of the system user.
 
@@ -191,6 +216,11 @@ defmodule Mv.Helpers.SystemActor do
   @spec system_user_email() :: String.t()
   def system_user_email, do: system_user_email_config()
 
+  # Case-insensitive normalized form for comparisons
+  defp normalized_system_user_email, do: normalized_email(system_user_email_config())
+
+  defp normalized_email(email) when is_binary(email), do: String.downcase(email)
+
   # Returns the system user email from environment variable or default
   # This allows configuration via SYSTEM_ACTOR_EMAIL env var
   @spec system_user_email_config() :: String.t()
@@ -368,7 +398,7 @@ defmodule Mv.Helpers.SystemActor do
       upsert_identity: :unique_email,
       authorize?: false
     )
-    |> Ash.Changeset.for_update(:update, %{})
+    |> Ash.Changeset.for_update(:update_internal, %{})
     |> Ash.Changeset.manage_relationship(:role, admin_role, type: :append_and_remove)
     |> Ash.update!(authorize?: false)
     |> Ash.load!(:role, domain: Mv.Accounts, authorize?: false)

test/mv/helpers/system_actor_test.exs

@@ -57,7 +57,7 @@ defmodule Mv.Helpers.SystemActorTest do
          |> Ash.read_one(domain: Mv.Accounts, authorize?: false) do
       {:ok, user} when not is_nil(user) ->
         user
-        |> Ash.Changeset.for_update(:update, %{})
+        |> Ash.Changeset.for_update(:update_internal, %{})
         |> Ash.Changeset.manage_relationship(:role, admin_role, type: :append_and_remove)
         |> Ash.update!(authorize?: false)
         |> Ash.load!(:role, domain: Mv.Accounts, authorize?: false)
@@ -68,7 +68,7 @@ defmodule Mv.Helpers.SystemActorTest do
           upsert_identity: :unique_email,
           authorize?: false
         )
-        |> Ash.Changeset.for_update(:update, %{})
+        |> Ash.Changeset.for_update(:update_internal, %{})
         |> Ash.Changeset.manage_relationship(:role, admin_role, type: :append_and_remove)
         |> Ash.update!(authorize?: false)
         |> Ash.load!(:role, domain: Mv.Accounts, authorize?: false)
@@ -373,9 +373,9 @@ defmodule Mv.Helpers.SystemActorTest do
 
       system_actor = SystemActor.get_system_actor()
 
-      # Assign wrong role to system user
+      # Assign wrong role to system user (use :update_internal so bootstrap-style update is allowed)
       system_user
-      |> Ash.Changeset.for_update(:update, %{})
+      |> Ash.Changeset.for_update(:update_internal, %{})
       |> Ash.Changeset.manage_relationship(:role, read_only_role, type: :append_and_remove)
       |> Ash.update!(actor: system_actor)