Identify and implement top 5 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 :)

Five folds in apps/api, −47 production lines (−51 with registers) across 19 files + a new retry-ladder test; no behaviour change. Quick gate, 2,355 changed-area API tests, blind code/security/verifier lanes all green. PR #7944 queued to the merge lane. Premise "massive" is spent after six dedupe passes; census in the report.