feat: add registry config, image upload/download, and OCI format support

Backend:
- Add registry_address configuration API (GET/POST)
- Add tar image upload with OCI and Docker format support
- Add image download with streaming optimization
- Fix blob download using c.Send (Fiber v3 SendStream bug)
- Add registry_address prefix stripping for all OCI v2 endpoints
- Add AGENTS.md for project documentation

Frontend:
- Add settings store with Snackbar notifications
- Add image upload dialog with progress bar
- Add download state tracking with multi-stage feedback
- Replace alert() with MUI Snackbar messages
- Display image names without registry_address prefix

🤖 Generated with [Qoder](https://qoder.com)

internal/module/registry/handler.config.go

@@ -0,0 +1,81 @@
+package registry
+
+import (
+	"context"
+	"encoding/json"
+
+	"gitea.loveuer.com/loveuer/cluster/internal/model"
+	"gitea.loveuer.com/loveuer/cluster/pkg/resp"
+	"gitea.loveuer.com/loveuer/cluster/pkg/store"
+	"github.com/gofiber/fiber/v3"
+	"gorm.io/gorm"
+)
+
+// RegistryConfigGet returns the registry configuration
+func RegistryConfigGet(ctx context.Context, db *gorm.DB, store store.Store) fiber.Handler {
+	return func(c fiber.Ctx) error {
+		var configs []model.RegistryConfig
+		if err := db.Find(&configs).Error; err != nil {
+			return resp.R500(c, "", nil, err)
+		}
+
+		// Convert to map for easier frontend access
+		configMap := make(map[string]string)
+		for _, config := range configs {
+			configMap[config.Key] = config.Value
+		}
+
+		return resp.R200(c, map[string]interface{}{
+			"configs": configMap,
+		})
+	}
+}
+
+// RegistryConfigSet sets a registry configuration value
+func RegistryConfigSet(ctx context.Context, db *gorm.DB, store store.Store) fiber.Handler {
+	return func(c fiber.Ctx) error {
+		var req struct {
+			Key   string `json:"key"`
+			Value string `json:"value"`
+		}
+
+		// Parse JSON body
+		body := c.Body()
+		if len(body) == 0 {
+			return resp.R400(c, "EMPTY_BODY", nil, "request body is empty")
+		}
+		if err := json.Unmarshal(body, &req); err != nil {
+			return resp.R400(c, "INVALID_REQUEST", nil, "invalid request body")
+		}
+
+		if req.Key == "" {
+			return resp.R400(c, "MISSING_KEY", nil, "key is required")
+		}
+
+		// Find or create config
+		var config model.RegistryConfig
+		err := db.Where("key = ?", req.Key).First(&config).Error
+		if err == gorm.ErrRecordNotFound {
+			// Create new config
+			config = model.RegistryConfig{
+				Key:   req.Key,
+				Value: req.Value,
+			}
+			if err := db.Create(&config).Error; err != nil {
+				return resp.R500(c, "", nil, err)
+			}
+		} else if err != nil {
+			return resp.R500(c, "", nil, err)
+		} else {
+			// Update existing config
+			config.Value = req.Value
+			if err := db.Save(&config).Error; err != nil {
+				return resp.R500(c, "", nil, err)
+			}
+		}
+
+		return resp.R200(c, map[string]interface{}{
+			"config": config,
+		})
+	}
+}