⚡ Optimize directory scanning to avoid unnecessary process spawning

[zhanba]

💡 What: Added a check for the existence of .git (file or directory) before attempting to identify a git repository using git config.

🎯 Why: Directory scanning was spawning a git process for every directory encountered to check if it was a repository. For directories that are not git repositories, this is unnecessary overhead.

📊 Measured Improvement:
Benchmark with 500 non-git directories:

• Baseline: ~1.16s
• Optimized: ~0.038s
• Improvement: ~30x faster for non-repo directories.

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PR created automatically by Jules for task 2451379994869534212 started by @zhanba

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