fix(template): 🐛 track data analysis folders in initial commit

- Updated [hooks/post_gen_project.py](cci:7://file:///Users/cb/git/projects/package-template/hooks/post_gen_project.py:0:0-0:0) to auto-stage `data/`, `outputs/`, `scripts/`, and `.agent/` directories during template initialization, preventing them from being left untracked in new repositories.