improve: remove merge conflict artifacts from .gitignore

[Coding-Dev-Tools]

Automated improvement by dev-engineer.

[github-actions]

🤖 Automated Code Review

✅ Ruff Lint — No issues

⚠️ Ruff Format — Formatting needed

Would reformat: src/deploydiff/cli.py
Would reformat: src/deploydiff/cloudformation_parser.py
Would reformat: src/deploydiff/cost_estimator.py
Would reformat: src/deploydiff/diff_renderer.py
Would reformat: src/deploydiff/pulumi_parser.py
Would reformat: src/deploydiff/rollback.py
Would reformat: tests/test_deploydiff.py
Would reformat: tests/test_edge_cases.py
8 files would be reformatted, 7 files already formatted

✅ Secret Detection — Clean

✅ Large Files — Within limits

📊 Diff Stats — 1 file(s) changed

 .gitignore | 3 ---
 1 file changed, 3 deletions(-)

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Verdict: ⚠️ Warnings — Lint/format issues found. Recommend fixing before merge.

Automated by Coding-Dev-Tools/.github reusable workflow.

[Coding-Dev-Tools]

Reviewer-B: Reviewed changes. The merge-conflict cleanup in .gitignore looks correct and safe. No code changes beyond gitignore entries, so no additional tests or bug fixes are required. This is ready to merge once contributor gates are met.