chore: use json logger

internal/pkg/config/resource.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"context"
+	"log/slog"
 
 	"github.com/sethvargo/go-envconfig"
 )
@@ -11,6 +12,8 @@ type Cfg struct {
 	Cache      *ValkeyConfig `env:", prefix=CACHE_"`
 	Image      *ImageConfig  `env:", prefix=IMAGE_"`
 	Tracking   *UmamiConfig  `env:", prefix=TRACKING_"`
+
+	LogLevel slog.Level `env:"LOG_LEVEL, default=DEBUG"`
 }
 
 type WebdavConfig struct {