Add subcription feature

frontend/src/utils/navigation.ts

@@ -11,9 +11,13 @@ import type { SubscriptionTier } from '../api';
  * Generate register URL with proper query parameters
  *
  * @param planTier - Optional subscription plan tier (starter, professional, enterprise)
+ * @param billingCycle - Optional billing cycle ('monthly' or 'yearly')
  * @returns Register URL with appropriate query parameters
  *
  * @example
+ * // In pilot mode with plan and billing cycle selected
+ * getRegisterUrl('starter', 'yearly') // => '/register?pilot=true&plan=starter&billing_cycle=yearly'
+ *
  * // In pilot mode with plan selected
  * getRegisterUrl('starter') // => '/register?pilot=true&plan=starter'
  *
@@ -23,7 +27,7 @@ import type { SubscriptionTier } from '../api';
  * // Not in pilot mode with plan
  * getRegisterUrl('professional') // => '/register?plan=professional'
  */
-export const getRegisterUrl = (planTier?: SubscriptionTier | string): string => {
+export const getRegisterUrl = (planTier?: SubscriptionTier | string, billingCycle?: 'monthly' | 'yearly'): string => {
   const params = new URLSearchParams();
 
   // Add pilot parameter if pilot mode is enabled globally
@@ -36,6 +40,11 @@ export const getRegisterUrl = (planTier?: SubscriptionTier | string): string =>
     params.set('plan', planTier);
   }
 
+  // Add billing cycle parameter if specified
+  if (billingCycle) {
+    params.set('billing_cycle', billingCycle);
+  }
+
   const queryString = params.toString();
   return `/register${queryString ? '?' + queryString : ''}`;
 };