[Feature Request] Support for Variable Persistence (Outputs) in YAML Modules

Currently, the Nettacker YAML engine is "stateless" during multi-step scans. While modules can define multiple steps, there is no mechanism to extract a value from the response of Step 1 (e.g., a Session Cookie, CSRF Token, or UID) and use it in the request of Step 2.

This limitation prevents the implementation of complex exploit chains (like CVE-2025-47812) where a secondary request is required to confirm or trigger RCE using data from an initial authentication/injection step.

Proposed Enhancement

• Implement a session_vars dictionary within the Module execution flow.
• Add support for an outputs block in YAML steps that uses regex to capture data from headers or the response body.
• Implement placeholder replacement (e.g., {variable_name}) in url, headers, and data fields for subsequent steps.

I am happy to work on this and am currently developing a solution but if anybody would like to help contribute I am open to suggestions for better methods

Start by tracing the YAML engine's module execution flow and how multi-step requests currently process URLs, headers, data, and responses. Define how session_vars, regex-based outputs from headers or response bodies, and {variable_name} substitution should interact across steps; done means later steps can consume captured values for chained requests.