v2.1.0: Config Manager & Admin API Enhancements

Features

• Add ConfigManager GenServer for coordinating in-memory and runtime Caddy config
• Add Admin.Resources module with domain-specific helpers for common Caddy config paths
• Expand Admin API tests with 41 comprehensive test cases covering error handling and edge cases

Fixes

• Fix caddy_bin argument to correctly override saved config in ConfigProvider.init
• Fix ConfigProvider.start_link to properly handle nested list from supervisor child spec

Refactoring

• Remove Application.get_env(:caddy, :config) dependency from Request module
• Simplify config by using Caddy.Config.socket_file() and :admin_host app env
• Remove bundled config/config.exs - library config should be set by consuming application

Improvements

• Add comprehensive telemetry for config_manager and resources operations
• Add ConfigManager behavior for mockable testing
• Extend Admin API to support path-less config functions (post_config/1, put_config/1, patch_config/1, delete_config/0)