Remove NoActor module, improve Member validation, update docs

lib/mv/authorization/checks/no_actor.ex

@@ -1,70 +0,0 @@
-defmodule Mv.Authorization.Checks.NoActor do
-  @moduledoc """
-  Custom Ash Policy Check that allows actions when no actor is present.
-
-  **IMPORTANT:** This check ONLY works in test environment for security reasons.
-  In production/dev, ALL operations without an actor are denied.
-
-  ## Security Note
-
-  This check uses compile-time environment detection to prevent accidental
-  security issues in production. In production, ALL operations (including :create
-  and :read) will be denied if no actor is present.
-
-  For seeds and system operations in production, use an admin actor instead:
-
-      admin_user = get_admin_user()
-      Ash.create!(resource, attrs, actor: admin_user)
-
-  ## Usage in Policies
-
-      policies do
-        # Allow system operations without actor (TEST ENVIRONMENT ONLY)
-        # In test: All operations allowed
-        # In production: ALL operations denied (fail-closed)
-        bypass action_type([:create, :read, :update, :destroy]) do
-          authorize_if NoActor
-        end
-        
-        # Check permissions when actor is present
-        policy action_type([:read, :create, :update, :destroy]) do
-          authorize_if HasPermission
-        end
-      end
-
-  ## Behavior
-
-  - In test environment: Returns `true` when actor is nil (allows all operations)
-  - In production/dev: Returns `false` when actor is nil (denies all operations - fail-closed)
-  - Returns `false` when actor is present (delegates to other policies)
-  """
-
-  use Ash.Policy.SimpleCheck
-
-  # Compile-time check: Only allow no-actor bypass in test environment
-  # SECURITY: This must ONLY be true in test.exs, never in prod/dev
-  # Using compile_env instead of Mix.env() for release-safety
-  @allow_no_actor_bypass Application.compile_env(:mv, :allow_no_actor_bypass, false)
-
-  @impl true
-  def describe(_opts) do
-    if @allow_no_actor_bypass do
-      "allows actions when no actor is present (test environment only)"
-    else
-      "denies all actions when no actor is present (production/dev - fail-closed)"
-    end
-  end
-
-  @impl true
-  def match?(nil, _context, _opts) do
-    # Actor is nil
-    # SECURITY: Only allow if compile_env flag is set (test.exs only)
-    # No runtime Mix.env() check - fail-closed by default (false)
-    @allow_no_actor_bypass
-  end
-
-  def match?(_actor, _context, _opts) do
-    # Actor is present - don't match (let other policies decide)
-    false
-  end
-end