// Package ezconf provides a unified configuration management system for loading
// and managing environment-based configurations across multiple packages.
//
// ezconf allows you to:
//   - Load configurations from multiple packages using their ConfigFromEnv functions
//   - Parse config struct tags to extract environment variable documentation
//   - Generate and update .env files with all required environment variables
//   - Print environment variable lists with descriptions and current values
//   - Track additional custom environment variables
//
// # Basic Usage
//
// Create a configuration loader and register packages using built-in integrations (recommended):
//
//	import (
//		"git.haelnorr.com/h/golib/ezconf"
//		"git.haelnorr.com/h/golib/hlog"
//		"git.haelnorr.com/h/golib/hws"
//		"git.haelnorr.com/h/golib/hwsauth"
//	)
//
//	loader := ezconf.New()
//
//	// Register packages using built-in integrations
//	loader.RegisterIntegrations(
//		hlog.NewEZConfIntegration(),
//		hws.NewEZConfIntegration(),
//		hwsauth.NewEZConfIntegration(),
//	)
//
//	// Load all configurations
//	if err := loader.Load(); err != nil {
//		log.Fatal(err)
//	}
//
//	// Get a specific configuration
//	hlogCfg, ok := loader.GetConfig("hlog")
//	if ok {
//		cfg := hlogCfg.(*hlog.Config)
//		// Use configuration...
//	}
//
// Alternatively, you can manually register config structs:
//
//	loader := ezconf.New()
//
//	// Add config struct for tag parsing
//	loader.AddConfigStruct(&mypackage.Config{}, "MyPackage")
//
//	// Add configuration loaders
//	loader.AddConfigFunc("mypackage", func() (interface{}, error) {
//		return mypackage.ConfigFromEnv()
//	})
//
//	loader.Load()
//
// # Printing Environment Variables
//
// Print all environment variables with their descriptions:
//
//	// Print without values (useful for documentation)
//	if err := loader.PrintEnvVarsStdout(false); err != nil {
//		log.Fatal(err)
//	}
//
//	// Print with current values
//	if err := loader.PrintEnvVarsStdout(true); err != nil {
//		log.Fatal(err)
//	}
//
// # Generating .env Files
//
// Generate a new .env file with all environment variables:
//
//	// Generate with default values
//	err := loader.GenerateEnvFile(".env", false)
//
//	// Generate with current environment values
//	err := loader.GenerateEnvFile(".env", true)
//
// Update an existing .env file:
//
//	// Update existing file, preserving existing values
//	err := loader.UpdateEnvFile(".env", true)
//
// # Adding Custom Environment Variables
//
// You can add additional environment variables that aren't in package configs:
//
//	loader.AddEnvVar(ezconf.EnvVar{
//		Name:        "DATABASE_URL",
//		Description: "PostgreSQL connection string",
//		Required:    true,
//		Default:     "postgres://localhost/mydb",
//	})
//
// # Struct Tag Format
//
// ezconf uses struct tags to define environment variable metadata:
//
//	type Config struct {
//		LogLevel    string `ezconf:"LOG_LEVEL,description:Log level for the application,default:info"`
//		DatabaseURL string `ezconf:"DATABASE_URL,description:Database connection string,required"`
//		LogDir      string `ezconf:"LOG_DIR,description:Directory for log files,required:when LOG_OUTPUT is file"`
//	}
//
// Tag components (comma-separated):
//   - First value: environment variable name (required)
//   - description:...: Description of the variable
//   - default:...: Default value
//   - required: Marks the variable as required
//   - required:condition: Marks as required with a condition description
//
// # Integration
//
// Packages can implement the Integration interface to provide automatic
// registration with ezconf. The interface requires:
//   - Name() string: Registration key for the config
//   - ConfigPointer() any: Pointer to config struct for tag parsing
//   - ConfigFunc() func() (any, error): Function to load config from env
//   - GroupName() string: Display name for grouping env vars
//
// ezconf integrates with:
//   - All golib packages that follow the ConfigFromEnv pattern
//   - Any custom configuration structs with ezconf struct tags
//   - Standard .env file format
package ezconf