nav order matches page; pricing moved last; setup-intent attach fix

Page section order is now: hero → pillars → how-it-works → inference →
efficiency → comparison → enterprise → mission → local-first → safety →
environmental → marketplace → viral → pricing → footer. Pricing is the
last content block so visitors scroll the whole story before being asked
to commit. Nav (desktop + mobile + dropdown) reordered to mirror the
page: How it works → Enterprise → Mission ▾ → Marketplace → Pricing →
About / Gallery / Account.

Stripe attach bug: /api/link-customer was hitting
POST /v1/payment_intents/{id} for every Intent regardless of type, so
SetupIntents (seti_*) returned 404 from Stripe. Branched on the id
prefix - SetupIntents go to /v1/setup_intents/{id} and skip the
receipt_email param (PaymentIntent-only field). Caught from a live
422 in the dashboard the moment Will tested timing=later.

src/main.el

@@ -146,6 +146,10 @@ fn persist_founding_count(sold: Int) {
 // ── Page assembly ─────────────────────────────────────────────────────────────
 
 fn page(sold: Int, total: Int) -> String {
+    // Page order is the source of truth; nav must mirror it section-for-section.
+    // Pricing is intentionally last so a visitor can scroll the whole story
+    // (what / how / why / who-it's-for / safety / planet) before being asked
+    // to commit to a plan.
     return page_open()
         + nav()
         + hero()
@@ -159,9 +163,9 @@ fn page(sold: Int, total: Int) -> String {
         + local_first()
         + safety()
         + environmental()
-        + pricing(sold, total)
         + marketplace()
         + viral()
+        + pricing(sold, total)
         + footer()
         + page_close()
 }
@@ -521,11 +525,23 @@ fn handle_request(method: String, path: String, body: String) -> String {
             }
         }
 
-        // 3. Attach customer + receipt_email to the PaymentIntent
+        // 3. Attach customer to the live Intent. SetupIntents (seti_*) and
+        //    PaymentIntents (pi_*) live at different REST endpoints, so
+        //    branch on the id prefix. SetupIntents do not accept
+        //    receipt_email - that's a PaymentIntent-only field.
         if !str_eq(lc_cus_id, "") {
-            let lc_attach_body: String = "customer=" + lc_cus_id + "&receipt_email=" + lc_email_enc
-            let lc_attach_url:  String = "https://api.stripe.com/v1/payment_intents/" + lc_pi_id
-            let lc_attach:      String = http_post_form_auth(lc_attach_url, lc_attach_body, lc_auth)
+            let lc_is_setup: Bool = str_starts_with(lc_pi_id, "seti_")
+            let lc_attach_url: String = if lc_is_setup {
+                "https://api.stripe.com/v1/setup_intents/" + lc_pi_id
+            } else {
+                "https://api.stripe.com/v1/payment_intents/" + lc_pi_id
+            }
+            let lc_attach_body: String = if lc_is_setup {
+                "customer=" + lc_cus_id
+            } else {
+                "customer=" + lc_cus_id + "&receipt_email=" + lc_email_enc
+            }
+            let _lc_attach: String = http_post_form_auth(lc_attach_url, lc_attach_body, lc_auth)
         }
 
         // 4. Upsert the Supabase waitlist row so /account can find this purchase by email