fix: rename setInterval to setPricingInterval to stop shadowing window.setInterval

Custom setInterval(interval) in the pricing toggle script shadowed the
native window.setInterval. When Google Tag Manager loaded and called
setInterval(callback, ms), the custom function received a callback as
the interval arg, which matched neither 'monthly' nor 'yearly', hiding
all price elements on every language.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Christian Shearer

src/server/routes.ts

@@ -478,8 +478,8 @@ ${SUPPORTED_LANGS.map(l => `  <link rel="alternate" hreflang="${l}" href="${base
       <!-- Monthly / Yearly toggle -->
       <div style="display:flex;justify-content:center;margin-bottom:28px;">
         <div id="interval-toggle" style="display:inline-flex;background:var(--regen-gray-100);border-radius:10px;padding:4px;">
-          <button id="toggle-monthly" onclick="setInterval('monthly')" class="interval-btn interval-btn--active">${t(lang, "toggle_monthly")}</button>
-          <button id="toggle-yearly" onclick="setInterval('yearly')" class="interval-btn interval-btn--yearly">${t(lang, "toggle_yearly")} <span style="font-size:11px;font-weight:700;color:var(--regen-green);">${t(lang, "toggle_save")}</span></button>
+          <button id="toggle-monthly" onclick="setPricingInterval('monthly')" class="interval-btn interval-btn--active">${t(lang, "toggle_monthly")}</button>
+          <button id="toggle-yearly" onclick="setPricingInterval('yearly')" class="interval-btn interval-btn--yearly">${t(lang, "toggle_yearly")} <span style="font-size:11px;font-weight:700;color:var(--regen-green);">${t(lang, "toggle_save")}</span></button>
         </div>
       </div>
 
@@ -752,7 +752,7 @@ ${SUPPORTED_LANGS.map(l => `  <link rel="alternate" hreflang="${l}" href="${base
 
   <script>
     var currentInterval = 'monthly';
-    function setInterval(interval) {
+    function setPricingInterval(interval) {
       currentInterval = interval;
       var monthlyEls = document.querySelectorAll('.price-monthly');
       var yearlyEls = document.querySelectorAll('.price-yearly');
@@ -797,7 +797,7 @@ ${SUPPORTED_LANGS.map(l => `  <link rel="alternate" hreflang="${l}" href="${base
     function switchToYearly() {
       var tier = pendingTier;
       closeNudge();
-      setInterval('yearly');
+      setPricingInterval('yearly');
       doSubscribe(tier, 'yearly');
     }