Fix Zeitwerk load error for SanitizeConfig

"expected file app/lib/sanitize_config.rb to define constant
SanitizeConfig"

app/lib/sanitize/config.rb

@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+class Sanitize
+  module Config
+    HTTP_PROTOCOLS ||= ['http', 'https', 'dat', 'dweb', 'ipfs', 'ipns', 'ssb', 'gopher', :relative].freeze
+
+    CLASS_WHITELIST_TRANSFORMER = lambda do |env|
+      node = env[:node]
+      class_list = node['class']&.split(/[\t\n\f\r ]/)
+
+      return unless class_list
+
+      class_list.keep_if do |e|
+        next true if e =~ /^(h|p|u|dt|e)-/ # microformats classes
+        next true if e =~ /^(mention|hashtag)$/ # semantic classes
+        next true if e =~ /^(ellipsis|invisible)$/ # link formatting classes
+      end
+
+      node['class'] = class_list.join(' ')
+    end
+
+    GABSOCIAL_STRICT ||= freeze_config(
+      elements: %w(p br span a),
+
+      attributes: {
+        'a'    => %w(href rel class),
+        'span' => %w(class),
+      },
+
+      add_attributes: {
+        'a' => {
+          'rel' => 'nofollow noopener noreferrer',
+          'target' => '_blank',
+        },
+      },
+
+      protocols: {
+        'a' => { 'href' => HTTP_PROTOCOLS },
+      },
+
+      transformers: [
+        CLASS_WHITELIST_TRANSFORMER,
+      ]
+    )
+
+    GABSOCIAL_OEMBED ||= freeze_config merge(
+      RELAXED,
+      elements: RELAXED[:elements] + %w(audio embed iframe source video),
+
+      attributes: merge(
+        RELAXED[:attributes],
+        'audio'  => %w(controls),
+        'embed'  => %w(height src type width),
+        'iframe' => %w(allowfullscreen frameborder height scrolling src width),
+        'source' => %w(src type),
+        'video'  => %w(controls height loop width),
+        'div'    => [:data]
+      ),
+
+      protocols: merge(
+        RELAXED[:protocols],
+        'embed'  => { 'src' => HTTP_PROTOCOLS },
+        'iframe' => { 'src' => HTTP_PROTOCOLS },
+        'source' => { 'src' => HTTP_PROTOCOLS }
+      )
+    )
+  end
+end