feat(lab3): SSH commit signing + gitleaks pre-commit + history rewrite

[Meliman1000-7]

Goal

Configure SSH commit signing for cryptographic authorship verification, wire gitleaks into a pre-commit hook to block accidental secret commits, and practice history rewriting with git filter-repo.

Changes

• .pre-commit-config.yaml — gitleaks v8.21.2 + detect-private-key + check-added-large-files hooks
• submissions/lab3.md — triage report with SSH signing config, blocked commit evidence, tune-out exercise, and history rewrite documentation

Testing

SSH signing verification:

git log --show-signature -1
→ Good "git" signature for egor.neyalov@mail.ru with ED25519 key SHA256:VjXsGms5VaarmJ6Mk3UML8JHF/TCOUcF90EFeq9HRyE

Pre-commit hook installation:

pre-commit install
→ pre-commit installed at .git/hooks/pre-commit

gitleaks blocking a fake secret:

git commit -m "test: should be blocked by gitleaks"
→ hook id: gitleaks / exit code: 1 / RuleID: github-pat

Artifacts & Screenshots

• submissions/lab3.md
• .pre-commit-config.yaml
• Verified commit: Meliman1000-7@667d59c
• Screenshot of Verified badge:

Checklist

• Title is clear (feat(labN): <topic> style)
• No secrets or large temp files committed
• Submission file at submissions/lab3.md exists