Create synthetic DEB fixtures and automated parse/repackage tests

[112-stack]

Context

The DEB workbench needs redistributable test packages so extraction and repackaging changes can be validated without using proprietary jailbreak tweaks.

Goal

Build a tiny synthetic fixture set and an automated round-trip test.

Suggested scope

• Generate a minimal Debian package containing text files, nested paths, metadata, and one binary placeholder.
• License the fixture for redistribution and document how it is generated.
• Test package metadata parsing and file-tree creation.
• Modify one text file, repackage it, and verify the resulting archive can be parsed again.
• Include a negative fixture or test for unsafe paths such as ../.

Acceptance criteria

• No proprietary package content is committed.
• Fixture generation is reproducible.
• Tests cover parse, edit, and repackage behavior.
• Unsafe archive paths are rejected or safely normalized.
• The test command works on at least Windows and one Unix-like environment, or limitations are documented.