fix: refine .git directory exclusion regex

Improved the regex pattern used for matching the .git directory to
exclude cases such as nested .git folders and handle different
path separators on various operating systems. Removed the redundant
check in GatherFiles function as the new regex pattern covers all
cases for .git directory exclusion.

Author: emilkje

cmd/cwc.go

@@ -499,7 +499,7 @@ func gatherContext(opts *chatOptions) ([]filetree.File, *filetree.FileNode, erro
 	}
 
 	if excludeGitDirFlag {
-		gitDirMatcher, err := pathmatcher.NewRegexPathMatcher(`^.*\.git$`)
+		gitDirMatcher, err := pathmatcher.NewRegexPathMatcher(`^\.git(/|\\)`)
 		if err != nil {
 			return nil, nil, fmt.Errorf("error creating git directory matcher: %w", err)
 		}

pkg/filetree/filetree.go

@@ -47,11 +47,6 @@ func GatherFiles(opts *FileGatherOptions) ([]File, *FileNode, error) { //nolint:
 				return err
 			}
 
-			// start by skipping the .git directory
-			if strings.HasPrefix(path, ".git/") {
-				return nil
-			}
-
 			normalizedPath := filepath.ToSlash(path)
 			if !includeMatcher.Match(normalizedPath) || info.IsDir() || excludeMatcher.Match(normalizedPath) {
 				return nil