Function parse_gitignore 

pub fn parse_gitignore(root: &Path) -> Vec<String>

Parse .gitignore from root and return a list of simple directory/file names to exclude during traversal.

Strategy (matches the TS parseGitignore in sync-turbo-env.ts):

• Read .gitignore, split into lines
• Strip comments (#) and blank lines
• Normalize: remove leading / and trailing /
• Drop negations (!) and wildcard patterns (*) — too complex for simple component-based matching; these are already handled by git itself
• Always include .git and node_modules as safety nets