Enhance configuration management with comprehensive environment setup

- Added detailed .env.example with extensive configuration options
- Created centralized configuration module with type-safe environment variable loading
- Implemented configuration validation and default value handling
- Added support for different environment modes (development, production, test)
- Introduced interfaces for robust type definitions across the project
- Implemented middleware for request validation, security, and input sanitization

.env.example

@@ -1,7 +1,51 @@
-NODE_ENV=development
+# Home Assistant Configuration
+# The URL of your Home Assistant instance
 HASS_HOST=http://homeassistant.local:8123
+
+# Long-lived access token from Home Assistant
+# Generate from Profile -> Long-Lived Access Tokens
 HASS_TOKEN=your_home_assistant_token
-PORT=3000
+
+# WebSocket URL for real-time updates
 HASS_SOCKET_URL=ws://homeassistant.local:8123/api/websocket
-LOG_LEVEL=debug
-PROCESSOR_TYPE=claude
+
+# Server Configuration
+# Port for the MCP server (default: 3000)
+PORT=3000
+
+# Environment (development/production/test)
+NODE_ENV=development
+
+# Debug mode (true/false)
+DEBUG=false
+
+# Logging level (debug/info/warn/error)
+LOG_LEVEL=info
+
+# AI Configuration
+# Natural Language Processor type (claude/gpt4/custom)
+PROCESSOR_TYPE=claude
+
+# OpenAI API Key (required for GPT-4 analysis)
+OPENAI_API_KEY=your_openai_api_key
+
+# Rate Limiting
+# Requests per minute per IP for regular endpoints
+RATE_LIMIT_REGULAR=100
+
+# Requests per minute per IP for WebSocket connections
+RATE_LIMIT_WEBSOCKET=1000
+
+# Security
+# JWT secret for token generation (change this in production!)
+JWT_SECRET=your_jwt_secret_key
+
+# CORS configuration (comma-separated list of allowed origins)
+CORS_ORIGINS=http://localhost:3000,http://localhost:8123
+
+# Test Configuration
+# Only needed if running tests
+TEST_HASS_HOST=http://localhost:8123
+TEST_HASS_TOKEN=test_token
+TEST_HASS_SOCKET_URL=ws://localhost:8123/api/websocket
+TEST_PORT=3001