feat: init mirror-proxy project

- Docker Hub / GHCR / GitHub reverse proxy
- Web admin panel with link management
- Dynamic admin path, user and password config
- Rate limiting per link (dual/single auth mode)
- Docker and docker-compose deployment support
- GitHub Actions workflow for auto-publish to GHCR

internal/config/config.go

@@ -0,0 +1,125 @@
+package config
+
+import (
+	"encoding/json"
+	"os"
+	"sync"
+)
+
+type Config struct {
+	ListenAddr       string            `json:"listen_addr"`
+	AdminPath        string            `json:"admin_path"`
+	AdminUser        string            `json:"admin_user"`
+	AdminPass        string            `json:"admin_pass"`
+	DockerHubHost    string            `json:"docker_hub_host"`
+	GHCRCacheEnabled bool              `json:"ghcr_cache_enabled"`
+	CacheDir         string            `json:"cache_dir"`
+	MaxCacheSize     int64             `json:"max_cache_size"`
+	Links            map[string]*Link  `json:"links"`
+	mu               sync.RWMutex
+}
+
+type Link struct {
+	ID          string   `json:"id"`
+	Name        string   `json:"name"`
+	Token       string   `json:"token"`
+	Type        string   `json:"type"` // docker, ghcr, github
+	AuthMode    string   `json:"auth_mode"` // single, dual
+	Enabled     bool     `json:"enabled"`
+	RateLimit   int      `json:"rate_limit"` // requests per minute
+	CreatedAt   int64    `json:"created_at"`
+	AccessCount int64    `json:"access_count"`
+	LastAccess  int64    `json:"last_access"`
+}
+
+var (
+	cfg  *Config
+	once sync.Once
+)
+
+func Load(path string) (*Config, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			cfg = defaultConfig()
+			return cfg, cfg.Save(path)
+		}
+		return nil, err
+	}
+	cfg = defaultConfig()
+	if err := json.Unmarshal(data, cfg); err != nil {
+		return nil, err
+	}
+	if cfg.Links == nil {
+		cfg.Links = make(map[string]*Link)
+	}
+	return cfg, nil
+}
+
+func defaultConfig() *Config {
+	return &Config{
+		ListenAddr:       ":8080",
+		AdminPath:        "/admin",
+		AdminUser:        "admin",
+		AdminPass:        "admin123",
+		DockerHubHost:    "registry-1.docker.io",
+		GHCRCacheEnabled: true,
+		CacheDir:         "./cache",
+		MaxCacheSize:     10 * 1024 * 1024 * 1024, // 10GB
+		Links:            make(map[string]*Link),
+	}
+}
+
+func (c *Config) Save(path string) error {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	data, err := json.MarshalIndent(c, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(path, data, 0644)
+}
+
+func (c *Config) GetLink(id string) (*Link, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	link, ok := c.Links[id]
+	return link, ok
+}
+
+func (c *Config) GetLinkByToken(token string) (*Link, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	for _, link := range c.Links {
+		if link.Token == token {
+			return link, true
+		}
+	}
+	return nil, false
+}
+
+func (c *Config) SetLink(link *Link) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.Links[link.ID] = link
+}
+
+func (c *Config) DeleteLink(id string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	delete(c.Links, id)
+}
+
+func (c *Config) ListLinks() []*Link {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	links := make([]*Link, 0, len(c.Links))
+	for _, l := range c.Links {
+		links = append(links, l)
+	}
+	return links
+}
+
+func Get() *Config {
+	return cfg
+}