chore: remove unused form pages and newsletter component

Delete dead code: NewsletterForm component, .secret-form page, and
.form-success page. These are no longer used anywhere in the site.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/form/NewsletterForm.astro

@@ -1,61 +0,0 @@
----
-
----
-
-<div class="feedback-form">
-  <form
-    data-netlify="true"
-    data-netlify-honeypot="bot-field"
-    name="feedback"
-    method="POST"
-    action="/form-success"
-  >
-    <p class="hidden">
-      <label>
-        Don’t fill this out if you’re human: <input name="bot-field" />
-      </label>
-    </p>
-    <input type="hidden" name="form-name" value="feedback" />
-    <label for="name">Name</label>
-    <input id="name" type="text" name="name" />
-    <label for="email">Email</label>
-    <input id="email" type="email" name="email" required />
-    <button name="submit" type="submit">Submit</button>
-  </form>
-</div>
-
-<style>
-  .feedback-form {
-    min-width: 250px;
-    width: 45%;
-  }
-  label {
-    font-size: 16px;
-  }
-  input,
-  textarea,
-  button {
-    border-radius: 5px;
-    border: 1px solid #cbd5e1;
-    font-size: inherit;
-    margin: 15px 0;
-    padding: 12px 20px;
-    width: 100%;
-  }
-  button {
-    background-color: #2bdcd2;
-    border: 1px solid #2bdcd2;
-    color: #1e293b;
-    font-size: 16px;
-    width: 50%;
-  }
-  .hidden {
-    clip: rect(0 0 0 0);
-    clip-path: inset(50%);
-    height: 1px;
-    overflow: hidden;
-    position: absolute;
-    white-space: nowrap;
-    width: 1px;
-  }
-</style>

src/pages/.form-success.astro

@@ -1,22 +0,0 @@
----
-import BaseLayout from "../layouts/BaseLayout.astro";
-import "../styles/icons.css";
----
-
-<BaseLayout
-  title="Audacity Cloud Saving Platform"
-  description="Never lose your work in Audacity with seamless sync to Cloud Storage"
->
-  <section class="mx-8 max-w-screen-md xl:max-w-screen-lg md:mx-auto">
-    <div class="py-8 sm:py-12 flex flex-col items-center">
-      <div class="text-center">
-        <h1>
-          Submission successful, thanks!
-        </h1>
-        <div class="mt-12">
-          <a href="/" class="w-fit px-4 py-4 bg-gray-200 my-4 rounded-md hover:bg-gray-300 cursor-pointer">Continue</a>
-        </div>
-      </div>
-    </div>
-  </section>
-</BaseLayout>

src/pages/.secret-form.astro

@@ -1,20 +0,0 @@
----
-import NewsletterForm from "../components/form/NewsletterForm.astro";
-import BaseLayout from "../layouts/BaseLayout.astro";
-import "../styles/icons.css";
-
----
-
-<BaseLayout
-  title="Audacity Cloud Saving Platform"
-  description="Never lose your work in Audacity with seamless sync to Cloud Storage"
->
-  <section class="mx-8 max-w-screen-md xl:max-w-screen-lg md:mx-auto">
-    <div class="mt-8 flex flex-col items-center gap-8">
-      <h1>Sign up to our newsletter</h1>
-
-      <p>Current branch: {branch}</p>
-      <NewsletterForm />
-    </div>
-  </section>
-</BaseLayout>