Add Lemon Squeezy environment variable schema validation and removed NODE_ENV from production variables, as it causes issues in Vercel

- Implement `getLemonSqueezyEnv` function to validate required environment variables for Lemon Squeezy integration using `zod`.
- Ensure `LEMON_SQUEEZY_SECRET_KEY`, `LEMON_SQUEEZY_SIGNING_SECRET`, and `LEMON_SQUEEZY_STORE_ID` are present and valid.

apps/web/.env.production

@@ -5,9 +5,6 @@
 ## AVOID PLACING SENSITIVE DATA IN THIS FILE.
 ## PUBLIC KEYS OR CONFIGURATION ARE OKAY TO BE PLACED HERE.
 
-# NODE ENV
-NODE_ENV=production
-
 # SUPABASE
 NEXT_PUBLIC_SUPABASE_URL=
 

packages/billing/lemon-squeezy/src/schema/lemon-squeezy-server-env.schema.ts

@@ -1,11 +1,29 @@
 import { z } from 'zod';
 
+/**
+ * @name getLemonSqueezyEnv
+ * @description Get the Lemon Squeezy environment variables.
+ * It will throw an error if any of the required variables are missing.
+ */
 export const getLemonSqueezyEnv = () =>
   z
     .object({
-      secretKey: z.string().min(1),
-      webhooksSecret: z.string().min(1),
-      storeId: z.string(),
+      secretKey: z
+        .string({
+          description: `The secret key you created for your store. Please use the variable LEMON_SQUEEZY_SECRET_KEY to set it.`,
+        })
+        .min(1),
+      webhooksSecret: z
+        .string({
+          description: `The shared secret you created for your webhook. Please use the variable LEMON_SQUEEZY_SIGNING_SECRET to set it.`,
+        })
+        .min(1)
+        .max(40),
+      storeId: z
+        .string({
+          description: `The ID of your store. Please use the variable LEMON_SQUEEZY_STORE_ID to set it.`,
+        })
+        .min(1),
     })
     .parse({
       secretKey: process.env.LEMON_SQUEEZY_SECRET_KEY,