Unify page layouts, compact headers and shared UI styling

frontend/app/feedback/page.tsx

@@ -1,5 +1,7 @@
 'use client'
 
+import PageHeading from '../ui/PageHeading'
+
 import { useEffect, useState } from 'react'
 import { useRouter } from 'next/navigation'
 import { authFetchOrThrow, getApiBase, getToken, UnauthorizedError } from '../lib/auth'
@@ -78,16 +80,10 @@ export default function FeedbackPage() {
   }
 
   return (
-    <main className="card">
-      <header className="how-hero">
-        <p className="eyebrow">Send feedback</p>
-        <h1>Help us improve Magent</h1>
-        <p className="lede">
-          Found a problem or have an idea? Send it here and we will see it right away.
-        </p>
-      </header>
+    <main className="card feedback-page">
+      <PageHeading title="Feedback" description="Share an idea or tell us what could work better." />
 
-      <form className="auth-form" onSubmit={submit}>
+      <form className="account-panel account-form feedback-form" onSubmit={submit}>
         <label htmlFor="feedback-user">Your username</label>
         <input id="feedback-user" value={profile?.username ?? ''} readOnly />