feat(config): add comprehensive configuration management for FastKit

- Introduced `config.demo.ts` for demo environment variables.
- Created `config.env.create.ts` to generate `.env` files with demo content.
- Added `config.types.ts` for TypeScript type definitions related to configuration.
- Implemented `config.validation.ts` for Zod validation schemas for configuration types.
- Defined database configuration types in `db/Db.type.ts`.
- Added environment variable management in `env.manager.ts`.
- Established constants for environment variables in `constant/env.constant.ts`.
- Defined environment types in `type/env.types.ts`.

Author: abhishek-nexgen-dev

.env.example

@@ -0,0 +1,105 @@
+# ===============================================================
+# FastKit Environment Configuration
+# This file contains sample environment variables for FastKit
+# Copy this file to .env and modify the values as needed
+# ===============================================================
+
+# Server Configuration
+PORT=3000
+HOST=localhost
+NODE_ENV=development
+ENVIRONMENT=development
+# SERVER_TIMEOUT=30000
+# SERVER_KEEP_ALIVE=true
+# SERVER_BODY_LIMIT=100mb
+# SERVER_TRUST_PROXY=false
+
+# Database Configuration
+DATABASE_TYPE=mongodb
+DATABASE_URL=mongodb://localhost:27017/fastkit
+# DATABASE_HOST=localhost
+# DATABASE_PORT=27017
+# DATABASE_USERNAME=your_username
+# DATABASE_PASSWORD=your_password
+# DATABASE_NAME=fastkit
+# DATABASE_POOL_SIZE=10
+# DATABASE_CONNECTION_TIMEOUT=30000
+# DATABASE_SSL=false
+
+# JWT Configuration (Required)
+JWT_SECRET=your-super-secret-jwt-key-change-this-in-production-minimum-32-chars
+JWT_EXPIRES_IN=24h
+JWT_ALGORITHM=HS256
+# JWT_REFRESH_SECRET=your-refresh-secret-minimum-32-chars
+# JWT_REFRESH_EXPIRES_IN=7d
+# JWT_ISSUER=your-app
+# JWT_AUDIENCE=your-users
+# JWT_SUBJECT=auth
+
+# CORS Configuration (Optional)
+# CORS_ORIGIN=http://localhost:3000,https://yourdomain.com
+# CORS_METHODS=GET,POST,PUT,DELETE,PATCH
+# CORS_ALLOWED_HEADERS=Content-Type,Authorization
+# CORS_CREDENTIALS=true
+# CORS_MAX_AGE=86400
+
+# Security Configuration (Optional)
+# RATE_LIMIT_WINDOW_MS=900000
+# RATE_LIMIT_MAX=100
+# SECURITY_HELMET=true
+# SECURITY_COMPRESSION=true
+# SECURITY_MORGAN=true
+# SECURITY_CSRF=false
+
+# Email Configuration (Optional)
+# EMAIL_SERVICE=gmail
+# EMAIL_HOST=smtp.gmail.com
+# EMAIL_PORT=587
+# EMAIL_SECURE=false
+# EMAIL_USERNAME=your-email@gmail.com
+# EMAIL_PASSWORD=your-app-password
+# EMAIL_FROM=noreply@yourapp.com
+
+# Storage Configuration (Optional)
+# STORAGE_PROVIDER=local
+# STORAGE_BUCKET=your-bucket
+# STORAGE_REGION=us-east-1
+# STORAGE_ACCESS_KEY_ID=your-access-key
+# STORAGE_SECRET_ACCESS_KEY=your-secret-key
+# STORAGE_CDN_URL=https://cdn.yourapp.com
+
+# Cache Configuration (Optional)
+# CACHE_PROVIDER=memory
+# CACHE_HOST=localhost
+# CACHE_PORT=6379
+# CACHE_PASSWORD=your-redis-password
+# CACHE_TTL=3600
+# CACHE_PREFIX=fastkit:
+
+# Logging Configuration (Optional)
+# LOG_LEVEL=info
+# LOG_FORMAT=json
+# LOG_FILE_PATH=./logs/app.log
+# LOG_MAX_FILE_SIZE=10m
+# LOG_MAX_FILES=5
+
+# API Configuration (Optional)
+# API_VERSION=1.0.0
+# API_PREFIX=/api/v1
+# API_DOCS_URL=https://docs.yourapp.com
+# API_TIMEOUT=30000
+
+# Monitoring Configuration (Optional)
+# HEALTH_CHECK=true
+# HEALTH_CHECK_PATH=/health
+# METRICS=true
+# METRICS_PATH=/metrics
+# APM_ENABLED=false
+# APM_SERVICE_NAME=fastkit-app
+# APM_SERVER_URL=https://apm.yourapp.com
+# APM_API_KEY=your-apm-key
+
+# Custom Configuration (Optional)
+# APP_NAME=FastKit App
+# APP_VERSION=1.0.0
+# CUSTOM_DEBUG=true