Like actor_uuid_from_socket/1 but for a template's assigns map.

@spec actor_uuid_from_socket(struct() | map() | any()) :: String.t() | nil

Reads the current user's UUID from a LiveView socket's phoenix_kit_current_scope assign. Returns nil when the LV is mounted in a logged-out context (no scope, no user). LV callers thread the result into mutating context functions as actor_uuid: actor_uuid_from_socket(socket) so the activity log records who initiated the change.

@spec read_back_post(
  String.t(),
  term(),
  term() | nil,
  String.t() | nil,
  pos_integer() | nil
) ::
  {:ok, map()} | {:error, :not_found}

Reads a post back from DB using the appropriate method for the post's mode.

Used after create/update operations to return a consistent post map.