docs(lab2): submit lab 2

[Valdezzar]

Goal

Submit Lab 2. The PR shows Git object inspection, reflog recovery, signed tag verification, and a rebased feature branch.

Changes

• Added submissions/lab2.md
• Added one Git object chain: HEAD -> tree -> blob -> file
• Added .git directory inspection output
• Added reset disaster and reflog recovery output
• Added signed annotated tag verification output
• Added before and after rebase logs
• Added short notes about git gc, merge vs rebase, and --force-with-lease

Testing

I checked the Git object chain with git cat-file.

I created two signed Lab 2 commits, reset them away with git reset --hard HEAD~2, found them in git reflog, and recovered the latest one with git reset --hard.

I created and pushed the signed annotated tag v0.1.0-lab2-Valdezzar.

I rebased feature/lab2 on top of origin/main and pushed it with git push --force-with-lease.

Checklist

• One full object chain is documented
• Reflog output and recovery are documented
• Signed annotated tag is pushed and verified
• Before and after rebase logs are documented
• submissions/lab2.md updated