fix(web): use <p> for affiliates hero tagline

Change the hero description from <h2> to <p> so it no longer shares a
heading level with the semantic section headings, keeping the document
outline meaningful for screen readers and SEO. Same Vuetify typography
classes preserve the visual appearance.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: e720b62d-82e1-4d3c-b82e-11f3a2b7f7f8

Author: AchoArnold

web/app/pages/affiliates/index.vue

@@ -93,15 +93,15 @@ const scrollToFaq = () => {
           <h1 class="text-display-large font-weight-bold pb-1">
             Get paid to share httpSMS
           </h1>
-          <h2
+          <p
             class="text-medium-emphasis text-headline-small font-weight-light mt-8 mb-8"
           >
             Earn
             <span class="text-primary font-weight-bold">20% commission</span> —
             up to <span class="text-primary font-weight-bold">$70.00</span> — on
             every customer you refer. Recommend httpSMS on your blog, videos, or
             social, and we'll track every click and pay you.
-          </h2>
+          </p>
           <div>
             <VBtn
               color="primary"