🧪 Add unit tests for GitExecutor path validation

[giankpetrov]

🎯 What:

The testing gap addressed was the lack of unit tests for the GitExecutor._validateFilePath method, which is responsible for preventing path traversal vulnerabilities when executing Git commands.

📊 Coverage:

The following scenarios are now tested in src/git/gitExecutor.test.ts:

• Invalid Paths: ../outside.txt, ../../etc/passwd, absolute paths outside the repo, and deep traversal attempts (sub/../../../outside).
• Valid Paths: Standard file names, nested files (src/index.ts), local references (./local.file), and the repo root ("").
• Methods: diff, stage (multiple files), unstage, checkoutFile, cleanFile, and blame.

✨ Result:

• Increased test coverage for the core Git execution engine.
• Improved reliability of security-critical path validation logic.
• Enhanced codebase compatibility with the Node.js native test runner by isolating vscode imports and removing enum syntax in shared types.

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PR created automatically by Jules for task 5599091117584387295 started by @giankpetrov

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