chore: add .env support with gitignore protection

Add .env/.env.* to gitignore to prevent secret leaks, provide
.env.example with all billing env vars, and use Node 22 --env-file
flag in start/dev scripts for automatic loading.

Author: PierreBrisorgueil

.env.example

@@ -0,0 +1,10 @@
+# Stripe Billing
+# Get your keys from https://dashboard.stripe.com/test/apikeys
+DEVKIT_NODE_stripe_secretKey=sk_test_xxx
+DEVKIT_NODE_stripe_webhookSecret=whsec_xxx
+
+# Stripe Price IDs — create products at https://dashboard.stripe.com/test/products
+DEVKIT_NODE_stripe_prices_starter_monthly=price_xxx
+DEVKIT_NODE_stripe_prices_starter_annual=price_xxx
+DEVKIT_NODE_stripe_prices_pro_monthly=price_xxx
+DEVKIT_NODE_stripe_prices_pro_annual=price_xxx

.gitignore

@@ -19,6 +19,10 @@ coverage/
 
 # waos Node app and assets
 # ======================
+# Environment files (secrets)
+.env
+.env.*
+!.env.example
 public/dist/
 public/swagger.yml
 config/env/local.js

package.json

@@ -23,8 +23,8 @@
     "node": ">=22.0.0"
   },
   "scripts": {
-    "start": "node server.js",
-    "dev": "node --watch server.js",
+    "start": "node --env-file=.env server.js",
+    "dev": "node --env-file=.env --watch server.js",
     "debug": "nodemon --inspect server.js",
     "prod": "cross-env NODE_ENV=production node server.js --name=node",
     "test": "cross-env NODE_ENV=test NODE_OPTIONS=--experimental-vm-modules jest --runInBand --testPathPatterns='unit'",