Add complete project structure and all files

backend/.env.example

@@ -0,0 +1,30 @@
+# ============================================
+# Server Panel Backend Configuration
+# ============================================
+
+# Application
+PANEL_NAME=Server Panel
+DEBUG=false
+LOG_LEVEL=INFO
+
+# Database (matches docker-compose)
+DB_HOST=db
+DB_PORT=5432
+DB_USER=serverpanel
+DB_PASSWORD=serverpanel_secure_password
+DB_NAME=serverpanel
+DATABASE_URL=postgresql://serverpanel:serverpanel_secure_password@db:5432/serverpanel
+
+# JWT Authentication
+SECRET_KEY=your-very-secure-secret-key-change-this-in-production-minimum-32-chars
+ALGORITHM=HS256
+ACCESS_TOKEN_EXPIRE_MINUTES=1440
+
+# SSH Configuration
+SSH_TIMEOUT=10
+DEFAULT_SSH_USER=root
+DEFAULT_SSH_PORT=22
+
+# Security
+CORS_ORIGINS=*
+ALLOWED_HOSTS=localhost,127.0.0.1