Fix integration tests: correct vault derivation index and debug test failures

internal/vault/secrets_version_test.go

@@ -1,3 +1,20 @@
+// Vault-Level Version Operation Tests
+//
+// Integration tests for vault-level version operations:
+//
+// - TestVaultAddSecretCreatesVersion: Tests that AddSecret creates proper version structure
+// - TestVaultAddSecretMultipleVersions: Tests creating multiple versions with force flag
+// - TestVaultGetSecretVersion: Tests retrieving specific versions and current version
+// - TestVaultVersionTimestamps: Tests timestamp logic (notBefore/notAfter) across versions
+// - TestVaultGetNonExistentVersion: Tests error handling for invalid versions
+// - TestUpdateVersionMetadata: Tests metadata update functionality
+//
+// Version Management:
+// - List versions in reverse chronological order
+// - Promote any version to current
+// - Promotion doesn't modify timestamps
+// - Metadata remains encrypted and intact
+
 package vault
 
 import (