The Debian Nix package causes flake builds to fail inside the test and
container environment due to sandboxing and patched Nix behavior.
To ensure consistent behaviour across all distributions and align
container logic with production logic, pkgmgr now relies on its own
`init-nix.sh` bootstrap script instead of the distro’s `nix` package.
Dropping `Depends: nix` guarantees that both Debian containers and real
Debian systems install and initialize Nix via the upstream installer,
matching the behaviour on Arch, Fedora, and Ubuntu.
https://chatgpt.com/share/693ab9bf-e6ac-800f-83ba-a4abd1bfe407
- Add dev runner main.py that prefers local src/ over installed pkgmgr
- Move Arch/Debian/Fedora packaging files under packaging/* and update build scripts
- Adjust .gitignore/.dockerignore for new packaging paths and src/source/
- Improve config defaults discovery to support src/ layout and installed packages
- Update architecture diagram and add TODO overview for TAGS/MIRROR/SIGNING_KEY
https://chatgpt.com/share/693a76a0-e408-800f-9939-868524cbef4d
