docs(lab2): finish version control deep dive

[MiniMaxC]

Goal

Submit Lab 2 work covering Git internals, disaster recovery, signed tags, and rebasing.

Changes

• Added submissions/lab2.md with Lab 2 documentation.
• Demonstrated Git object inspection using commits, trees, and blobs.
• Simulated accidental history loss with git reset --hard and recovered using git reflog.
• Created and verified a signed annotated release tag.
• Rebasing feature/lab2 onto updated main and pushed using --force-with-lease.

Testing

Verified the work locally using:

• git status
• git log --oneline --graph --decorate --all -n 20
• git reflog
• git tag -v
• git cat-file
• git push --force-with-lease origin feature/lab2

Checklist

• Title is a clear sentence (≤ 70 chars)
• Commits are signed (git log --show-signature)
• submissions/lab2.md updated