docs(hacktober): reconcile PR tracker with live queue (84 resolved) (#15200)

Checked off 84 tracked PRs that are no longer open since the 2026-09-05
refresh: 10 merged and 74 closed. Updated the checkboxes across both the
main list and the by-directory grouping, and refreshed the 'Latest
refresh' summary line (approximately 669 PRs remain open).

Per #15081.

Author: priya-sundaram-dev