chore: catch up Storybook preview, coverage, and story hygiene

Stories were throwing without AuthModal/CreateFlow providers, autodocs was a no-op, and several DS/create-flow screens had no stories.

stories/controls/AddCustomField.stories.js

@@ -1,7 +1,5 @@
 import React, { useState } from "react";
 import AddCustomField from "../../app/components/controls/AddCustomField";
-import { MessagesProvider } from "../../app/contexts/MessagesContext";
-import messages from "../../messages/en/index";
 
 /** Figma: Add Custom Field — node `20235:12994` (Community Rule System). */
 export default {
@@ -9,11 +7,9 @@ export default {
   component: AddCustomField,
   decorators: [
     (Story) => (
-      <MessagesProvider messages={messages}>
-        <div className="w-[min(100%,546px)] bg-[var(--color-surface-default-primary)] p-6">
-          <Story />
-        </div>
-      </MessagesProvider>
+      <div className="w-[min(100%,546px)] bg-[var(--color-surface-default-primary)] p-6">
+        <Story />
+      </div>
     ),
   ],
 };