feat: add support for brace expansion in glob patterns

[hashemix]

📌 Summary

Previously, our glob pattern implementation only supported Unix shell–style patterns such as *, ?, **, and character classes like [a-z]. However, it did not support brace expansions (e.g., .{ts,java}), which limited pattern expressiveness for users.

This change adds support for brace expansion, allowing glob patterns like:

src/{main,test}.rs → matches src/main.rs and src/test.rs

images/{.jpg,.png} → matches all .jpg and .png files in images/

Nested braces like {a,{b,c}} are also supported (to the extent of the underlying glob implementation)

This enhancement improves compatibility with more expressive glob patterns and aligns our behavior with broader glob syntax expectations.

🔍 Related Issues

• Fixes search_files does not match brace-expanded patterns like **/*.{java,ts} (returns “No matches found”), while single-extension patterns work #50

🛠️ Testing Steps

cargo make check