docs: add per package README for implementation details (AI generated with human review)

cmd/README.md

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+# cmd
+
+Main entry point package for GoDoxy, a lightweight reverse proxy with WebUI for Docker containers.
+
+## Overview
+
+This package contains the `main.go` entry point that initializes and starts the GoDoxy server. It coordinates the initialization of all core components including configuration loading, API server, authentication, and monitoring services.
+
+## Architecture
+
+```mermaid
+graph TD
+    A[main] --> B[Init Profiling]
+    A --> C[Init Logger]
+    A --> D[Parallel Init]
+    D --> D1[DNS Providers]
+    D --> D2[Icon Cache]
+    D --> D3[System Info Poller]
+    D --> D4[Middleware Compose Files]
+    A --> E[JWT Secret Setup]
+    A --> F[Create Directories]
+    A --> G[Load Config]
+    A --> H[Start Proxy Servers]
+    A --> I[Init Auth]
+    A --> J[Start API Server]
+    A --> K[Debug Server]
+    A --> L[Uptime Poller]
+    A --> M[Watch Changes]
+    A --> N[Wait Exit]
+```
+
+## Main Function Flow
+
+The `main()` function performs the following initialization steps:
+
+1. **Profiling Setup**: Initializes pprof endpoints for performance monitoring
+1. **Logger Initialization**: Configures zerolog with memory logging
+1. **Parallel Initialization**: Starts DNS providers, icon cache, system info poller, and middleware
+1. **JWT Secret**: Ensures API JWT secret is set (generates random if not provided)
+1. **Directory Preparation**: Creates required directories for logs, certificates, etc.
+1. **Configuration Loading**: Loads YAML configuration and reports any errors
+1. **Proxy Servers**: Starts HTTP/HTTPS proxy servers based on configuration
+1. **Authentication**: Initializes authentication system with access control
+1. **API Server**: Starts the REST API server with all configured routes
+1. **Debug Server**: Starts the debug page server (development mode)
+1. **Monitoring**: Starts uptime and system info polling
+1. **Change Watcher**: Starts watching for Docker container and configuration changes
+1. **Graceful Shutdown**: Waits for exit signal with configured timeout
+
+## Configuration
+
+The main configuration is loaded from `config/config.yml`. Required directories include:
+
+- `logs/` - Log files
+- `config/` - Configuration directory
+- `certs/` - SSL certificates
+- `proxy/` - Proxy-related files
+
+## Environment Variables
+
+- `API_JWT_SECRET` - Secret key for JWT authentication (optional, auto-generated if not set)
+
+## Dependencies
+
+- `internal/api` - REST API handlers
+- `internal/auth` - Authentication and ACL
+- `internal/config` - Configuration management
+- `internal/dnsproviders` - DNS provider integration
+- `internal/homepage` - WebUI dashboard
+- `internal/logging` - Logging infrastructure
+- `internal/metrics` - System metrics collection
+- `internal/route` - HTTP routing and middleware
+- `github.com/yusing/goutils/task` - Task lifecycle management