Identify and implement top five code reduction

Identify top 5 opportunities to massively reduce the amount of code (lines of code) in any part of the repo: - Similar functionality that can be unified and reused - Code that has been valuable but no more - A front end component or a group of them duplicate another component/page functionality. Use the most modern and nice looking - etc. Now implement them :)

Census found the repo already deduplicated; implemented the two real reductions (migrations system-cron helper folding 8 revisions; Production QA test readers), net −301 lines. Quick gate, changed-area suites, code review and verifier green. PR #7947 queued to the merge lane. Three further opportunities identified and declined/deferred with reasons in the report (credential testers net ≈ 0; terraform needs plan/apply gate; selftests/wrappers are not reductions). Memory: used mem-25288; proposed none.