feat: add SSH and DNS asset import utilities

- Add ssh_exec() and ssh_rsync() functions for remote command execution and file transfer with connection pooling
- Add db_import_dns_asset() to import DNS zone records and group by domain with A/AAAA records stored separately
- Add db_import_custom_asset() for flexible JSONL asset import with direct field mapping, supporting tags and custom asset types
- Extend Asset model with ExternalURL, Remarks (string array), Language, Size, and LOC fields for better metadata tracking
- Add backward compatibility layer for legacy JSON formats (string remarks, tags array merging)
- Register new functions in function registry with proper documentation and usage examples

internal/executor/function_executor.go

@@ -45,6 +45,9 @@ func (e *FunctionExecutor) Execute(ctx context.Context, step *core.Step, execCtx
 	}
 
 	vars := execCtx.GetVariables()
+	if step.SuppressDetails {
+		vars["SuppressDetails"] = true
+	}
 	var outputs []interface{}
 	var err error