fix: add nolint comments for necessary global variables in internal/secret

Add nolint:gochecknoglobals comments for legitimate global variables:
- debugEnabled and debugLogger: Package-wide debug state management
- GPGEncryptFunc and GPGDecryptFunc: Required for test mocking
- getCurrentVaultFunc: Required to break import cycle between packages

internal/secret/debug.go

@@ -13,8 +13,8 @@ import (
 )
 
 var (
-	debugEnabled bool
-	debugLogger  *slog.Logger
+	debugEnabled bool         //nolint:gochecknoglobals // Package-wide debug state is necessary
+	debugLogger  *slog.Logger //nolint:gochecknoglobals // Package-wide logger instance is necessary
 )
 
 func init() {