Add environment configuration examples and quick start guide

- Add backend/.env.example with all required and optional variables
- Add frontend/.env.example with Next.js public variables
- Create QUICK_START.md for team onboarding
- Include submodule cloning instructions

backend/.env.example

@@ -0,0 +1,25 @@
+# ASLE Backend Environment Configuration
+# Copy this file to .env and fill in your values
+
+# REQUIRED
+DATABASE_URL="postgresql://user:password@localhost:5432/asle?schema=public"
+JWT_SECRET="your-super-secret-jwt-key-change-this-in-production"
+PORT=4000
+NODE_ENV=development
+LOG_LEVEL=info
+RPC_URL="https://eth-mainnet.g.alchemy.com/v2/YOUR_API_KEY"
+DIAMOND_ADDRESS="0x0000000000000000000000000000000000000000"
+CHAIN_ID=1
+
+# OPTIONAL: Push Notifications
+# FIREBASE_SERVICE_ACCOUNT="path/to/service-account.json"
+# ONESIGNAL_APP_ID="your-onesignal-app-id"
+# ONESIGNAL_API_KEY="your-onesignal-api-key"
+
+# OPTIONAL: KYC/AML Providers
+# SUMSUB_APP_TOKEN="your-sumsub-app-token"
+# JUMIO_API_TOKEN="your-jumio-api-token"
+# VERIFF_API_KEY="your-veriff-api-key"
+
+# OPTIONAL: Redis
+# REDIS_URL="redis://localhost:6379"