Remove unused PolicyHelpers macro and PolicyConsistency test

Dead code - macro was never used in codebase.
PolicyConsistency test will be replaced with better implementation.

lib/mv/authorization/policy_helpers.ex

@@ -1,40 +0,0 @@
-defmodule Mv.Authorization.PolicyHelpers do
-  @moduledoc """
-  Policy helpers for consistent bypass vs HasPermission patterns.
-
-  ## Pattern: READ Bypass + UPDATE HasPermission
-
-  For resources with scope :own/:linked permissions:
-  - READ: Use bypass with expr() for auto_filter
-  - UPDATE/CREATE/DESTROY: Use HasPermission for scope evaluation
-
-  ## Usage
-
-      use Mv.Authorization.PolicyHelpers
-
-      policies do
-        # Standard pattern for User resource
-        standard_user_policies()
-      end
-
-  ## Why This Pattern?
-
-  See `docs/policy-bypass-vs-haspermission.md` for detailed explanation.
-  """
-
-  defmacro standard_user_policies do
-    quote do
-      # READ: Bypass for auto_filter
-      bypass action_type(:read) do
-        description "Users can read their own records"
-        authorize_if expr(id == ^actor(:id))
-      end
-
-      # UPDATE/CREATE/DESTROY: HasPermission
-      policy action_type([:update, :create, :destroy]) do
-        description "Check permissions from role"
-        authorize_if Mv.Authorization.Checks.HasPermission
-      end
-    end
-  end
-end