Fix: track only untracked paths in ghost snapshots

[lionel-oai]

Ghost snapshot ignores

This PR should close #7067, #7395, #7405.

Prior to this change the ghost snapshot task ran git status --ignored=matching so the report picked up literally every ignored file. When a directory only contained entries matched by patterns such as dozens/*.txt, /test123/generated/*.html, or /wp-includes/*, Git still enumerated them and the large-untracked-dir detection treated the parent directory as “large,” even though everything inside was intentionally ignored.

By removing --ignored=matching we only capture true untracked paths now, so those patterns stay out of the snapshot report and no longer trigger the “large untracked directories” warning.