fix: resolve subscription ID lookup and checkout URL issues

- Fix getBaseUrl() ReferenceError by changing to resolveBaseUrl(req) for free-to-paid upgrades
- Add subscription lookup by customer email when dodoSubscriptionId is missing
- Log critical issues when paid users have no subscription ID in database or Dodo
- Return clear error message to contact support when subscription cannot be found
- Prevent silent failures in plan changes from settings page

chat/public/apps.html

@@ -2247,7 +2247,7 @@
       }
 
       const tourSteps = [
-        { target: null, color: '#008060' },
+        { target: '#apps-content', color: '#008060' },
         { target: '#create-new-app', color: '#5A31F4' },
         { target: '#upload-app-btn', color: '#F59E0B' },
         { target: '#browse-templates-btn', color: '#10B981' },

chat/server.js

@@ -12115,6 +12115,62 @@ async function handleAccountSettingsUpdate(req, res) {
     const isPaidToPaid = PAID_PLANS.has(user.plan) && PAID_PLANS.has(requestedPlan);
     const isFreeToPaid = user.plan === 'hobby' && PAID_PLANS.has(requestedPlan);
 
+    // Helper function to lookup subscription by customer
+    async function lookupSubscriptionByCustomer(user) {
+      try {
+        const customerId = await ensureDodoCustomer(user);
+        if (!customerId) return null;
+        
+        const subscriptions = await dodoRequest('/subscriptions', {
+          method: 'GET',
+          query: { customer_id: customerId, status: 'active' }
+        });
+        
+        if (subscriptions?.items && subscriptions.items.length > 0) {
+          const activeSub = subscriptions.items[0];
+          log('Found missing subscription ID via Dodo lookup', {
+            userId: user.id,
+            email: user.email,
+            subscriptionId: activeSub.subscription_id || activeSub.id,
+            customerId
+          });
+          return activeSub.subscription_id || activeSub.id;
+        }
+        return null;
+      } catch (error) {
+        log('Failed to lookup subscription by customer', {
+          userId: user.id,
+          email: user.email,
+          error: String(error)
+        });
+        return null;
+      }
+    }
+
+    // If paid user is missing dodoSubscriptionId, try to look it up
+    if ((isPaidToFree || isPaidToPaid) && !user.dodoSubscriptionId && PAID_PLANS.has(user.plan)) {
+      const foundSubscriptionId = await lookupSubscriptionByCustomer(user);
+      if (foundSubscriptionId) {
+        user.dodoSubscriptionId = foundSubscriptionId;
+        await persistUsersDb();
+        log('Recovered missing subscription ID', {
+          userId: user.id,
+          email: user.email,
+          subscriptionId: foundSubscriptionId
+        });
+      } else {
+        // Log the issue for investigation
+        log('CRITICAL: Paid user missing dodoSubscriptionId and no active subscription found in Dodo', {
+          userId: user.id,
+          email: user.email,
+          currentPlan: user.plan,
+          requestedPlan: requestedPlan,
+          billingStatus: user.billingStatus,
+          subscriptionRenewsAt: user.subscriptionRenewsAt
+        });
+      }
+    }
+
     // Schedule cancellation at period end when changing from paid to free hobby plan
     // User keeps premium features until the end of their billing period
     if (isPaidToFree && user.dodoSubscriptionId) {
@@ -12171,6 +12227,19 @@ async function handleAccountSettingsUpdate(req, res) {
         return sendJson(res, 400, { error: error.message || 'Unable to change subscription plan' });
       }
     }
+    // Handle paid-to-free or paid-to-paid when subscription ID is still missing after lookup
+    else if ((isPaidToFree || isPaidToPaid) && !user.dodoSubscriptionId) {
+      log('ERROR: Cannot change plan - paid user missing dodoSubscriptionId after lookup', {
+        userId: user.id,
+        email: user.email,
+        currentPlan: user.plan,
+        requestedPlan: requestedPlan,
+        changeType: isPaidToFree ? 'paid_to_free' : 'paid_to_paid'
+      });
+      return sendJson(res, 400, { 
+        error: 'Subscription ID not found. Please contact support to resolve this issue.' 
+      });
+    }
     // For free-to-paid upgrades, create a checkout session and return the URL
     else if (isFreeToPaid || (!user.dodoSubscriptionId && PAID_PLANS.has(requestedPlan))) {
       try {
@@ -12217,7 +12286,7 @@ async function handleAccountSettingsUpdate(req, res) {
           },
         };
         
-        const returnUrl = `${getBaseUrl()}/subscription-success`;
+        const returnUrl = `${resolveBaseUrl(req)}/subscription-success`;
         checkoutBody.return_url = returnUrl;
         
         const checkoutSession = await dodoRequest('/checkouts', {