⚡ Optimize submodule lookup by avoiding redundant string clones

[bashandbone]

💡 What: The optimization replaces entry.path.as_ref().map(|p| p.to_string()).unwrap_or(name.clone()) with entry.path.as_deref().unwrap_or(name) in src/git_ops/git2_ops.rs.

🎯 Why: The previous implementation forced heap allocations in two ways:

1. map(|p| p.to_string()) allocated a new string for path even though find_submodule only needs a &str.
2. unwrap_or(name.clone()) eagerly cloned the name string on every iteration, even when path was Some.

📊 Measured Improvement: I was unable to show a meaningful performance improvement using the provided cargo bench or cargo test because the environment lacked necessary dependencies (like bitflags) and had no network access to fetch them. However, the theoretical benefit is clear: it avoids at least one String allocation per submodule during the .gitmodules write operation, which is a significant reduction in overhead for repositories with many submodules. I verified the logical equivalence of the change using a standalone rustc script.

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PR created automatically by Jules for task 8596418518332672665 started by @bashandbone

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[Copilot]

Pull request overview

Optimizes submodule lookup during .gitmodules writing by avoiding unnecessary String allocations/clones when calling git2::Repository::find_submodule.

Changes:

• Replace to_string()/clone()-based temporary String construction with Option::as_deref() and unwrap_or on &str.
• Reduce per-submodule heap allocation overhead in write_gitmodules.

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