fix: resolve all golangci-lint errors

- Add blank lines before return statements (nlreturn)
- Remove unused metaCacheMu field and sync import (unused)
- Rename unused groups parameter to _ (revive)
- Use StorageFilePerm constant instead of magic 0600 (mnd, gosec)
- Add nolint directive for vipsOnce global (gochecknoglobals)

internal/logger/logger.go

@@ -40,12 +40,13 @@ func New(_ fx.Lifecycle, params Params) (*Logger, error) {
 	}
 
 	// replaceAttr simplifies the source attribute to "file.go:line"
-	replaceAttr := func(groups []string, a slog.Attr) slog.Attr {
+	replaceAttr := func(_ []string, a slog.Attr) slog.Attr {
 		if a.Key == slog.SourceKey {
 			if src, ok := a.Value.Any().(*slog.Source); ok {
 				a.Value = slog.StringValue(fmt.Sprintf("%s:%d", filepath.Base(src.File), src.Line))
 			}
 		}
+
 		return a
 	}