fix: ruff lint errors in sandbox_verifier.py (F401, F541)

[tcconnally]

Fixes 3 ruff lint errors causing CI failures on main:

• F401: Removed unused import json
• F401: Removed unused from typing import Any
• F541: Removed f prefix from f-string without placeholders

All found by ruff check src/ tests/ in CI.

[github-actions]

Note: PR Pilot suggested approval, but automated approval is disabled until changes are verified in a sandbox. Posting as a comment for human review.

🤖 PR Pilot Review

🔍 Reviewer (Agent 1)

This pull request resolves several ruff linting errors by removing unused imports and an unnecessary f-string prefix. The changes are straightforward, improve code cleanliness, and fix CI failures.

🔧 Fixer (Agent 2)

No findings to fix — nothing to do.

🧪 Tester (Agent 3)

The generated test covers the specific error path in the _apply_patch method where the patch command is not available, triggering a FileNotFoundError. This directly tests the changed line of code. Other paths within the _apply_patch method, such as successful patch application or other exceptions, are not covered by this new test.

✅ Verifier (Agent 4)

Verified one generated unit test for SandboxVerifier. The test correctly checks the error handling when the 'patch' command is not found by mocking subprocess.run to raise a FileNotFoundError. The test is syntactically correct, relevant, and its assertions are valid.

🚀 Decision: AUTO APPROVE

All checks passed. This PR is safe to merge.

Pipeline duration: ~47.3s

---

Review by PR Pilot — AI-native code quality service