Function worktree_dir_name 

pub fn worktree_dir_name(project: &str, branch: &str) -> String

Builds the worktree directory name from a project name and branch.

Replaces / with - and strips characters that are unsafe for directory names.

Examples

• ("git-paw", "feature/auth-flow") → "git-paw-feature-auth-flow"
• ("git-paw", "fix/db") → "git-paw-fix-db"