Remove unused recycle bin and add optional local file delete (#26)

Soft-delete restore/purge/list and the recycle_purge job are gone.
Admin delete now removes library index rows, with an optional
delete_files query that also deletes local media + sidecar NFO.
UI copy is renamed from 移入回收站 to 删除, with a confirm checkbox.

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: truewhile <truewhile@users.noreply.github.com>

internal/service/media_delete.go

@@ -0,0 +1,59 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"os"
+	"strings"
+
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// DeleteMedia removes a media row from the library index.
+// When deleteFiles is true and the path is a local filesystem file, the media
+// file and its sidecar NFO are also removed. cloud:// paths are never touched on disk.
+func (s *MediaService) DeleteMedia(ctx context.Context, id string, deleteFiles bool) error {
+	var media model.Media
+	err := s.repo.DB.WithContext(ctx).Where("id = ?", id).First(&media).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil
+		}
+		return err
+	}
+
+	if deleteFiles {
+		if err := deleteLocalMediaFiles(s.log, media.Path); err != nil {
+			return err
+		}
+	}
+
+	err = s.repo.DB.WithContext(ctx).Unscoped().Where("id = ?", id).Delete(&model.Media{}).Error
+	if err == nil {
+		s.invalidateMediaCache(ctx)
+	}
+	return err
+}
+
+func deleteLocalMediaFiles(log *zap.Logger, path string) error {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return nil
+	}
+	if strings.HasPrefix(strings.ToLower(path), "cloud://") {
+		if log != nil {
+			log.Info("skip local file delete for cloud media path", zap.String("path", path))
+		}
+		return nil
+	}
+	if err := removeMediaAndNFO(path); err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return nil
+		}
+		return err
+	}
+	return nil
+}