Add a Help page with FAQ and contact form

Adds a /help route with an animated FAQ accordion and a contact form
(persisted via a new contact_messages table). The per-order-item "Get
help" link now points here and passes the order/item/status as search
params, which the page uses to show a short, state-specific note and
prefill the message field.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/routes/__root.tsx

@@ -33,6 +33,9 @@ const RootDocument = ({ children }: { children: React.ReactNode }) => {
               <Logo name={brand.name} />
             </Link>
             <div className={styles.actions}>
+              <Link to="/help" className={styles.helpLink}>
+                Help
+              </Link>
               <BasketLink />
               <BetterAuthHeader />
             </div>