docs(lab2): submit Lab 2 version control deep dive

[linxel]

Goal

Submit Lab 2 work with Git internals, recovering lost commits, signed release tags, and rebasing feature branches.

Changes

• Created submissions/lab2.md with all task outputs
• Added signed annotated tag v0.1.0-lab2-ksu
• Rebased feature/lab2 branch onto origin/main
• Finished bonus git bisect task

Testing

• Recovered commits after hard reset using reflog
• Checked tag signature - got "Good" output
• Used bisect run to locate broken commit

Checklist

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