Add SSRF URL parser and redirect evidence gates

[cuph7022]

Summary

• Add the evidence gate requested by [REVIEW] secure-code-review: add SSRF URL parser and redirect revalidation gates #1702.
• Add a focused output table so reviewers capture the required proof consistently.
• Add a pitfall warning for the main bypass or unsupported-evidence risk.

Closes #1702

Validation

• Reviewed generated Markdown changes through the GitHub API.
• Confirmed the patch is scoped only to $(System.Collections.Hashtable.Path).
• Did not clone the repository, install dependencies, or run project code.