feat: add product-aware deletion emails and subdomain deletion/downloads routes

- Extend DeletionForm with product discriminator and configurable cooldown cookie
- Extract env-free deletion email helpers into deletion-email.ts with Lineage/Nessa branding
- Make misc.sendDeletionRequestEmail mutation product-aware (subject, html content, cookie)
- Replace legacy /deletion/life-and-lineage page with 308 redirect to lineage subdomain
- Add Lineage and Nessa subdomain deletion route modules with shared content components
- Add Lineage downloads route modules with shared content
- Update privacy policy deletion link to lineage subdomain

src/routes/privacy-policy/life-and-lineage.tsx

@@ -36,7 +36,7 @@ export default function PrivacyPolicy() {
                 <div class="-ml-6">(b) Data Removal:</div> Users can request the
                 removal of all information related to them by visiting{" "}
                 <A
-                  href="/deletion/life-and-lineage"
+                  href="https://lineage.freno.me/deletion"
                   class="text-blue hover-underline-animation"
                 >
                   this page