Apply the same user filter to every page of account members

Administrators see banned users in the account settings, but only the
first page counted them: the next pages listed active users alone. A
banned member before the page boundary shifted the offset, so one active
member was never listed. Both pages now share User.visible_to.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0142qgjggdJ2KDdGk7RF9Xm9

test/models/user/bannable_test.rb

@@ -0,0 +1,10 @@
+require "test_helper"
+
+class User::BannableTest < ActiveSupport::TestCase
+  test "banned users are visible to administrators only" do
+    users(:kevin).banned!
+
+    assert_includes User.visible_to(users(:david)), users(:kevin)
+    assert_not_includes User.visible_to(users(:jz)), users(:kevin)
+  end
+end