Reduce codebase by implementing top 5 opportunities

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 :)

Repo measured at its duplication floor (jscpd 0.01%/0.02%, no dead exports/modules). Implemented the 5 largest real opportunities: access picker twin deleted into ui/AsyncMultiLookup; 13 boolean settings on SettingCheckbox; fact lists on KeyValueList; 7 api alias shims removed; 7 ghost test assertions stripped. 70 files, net −163 lines. Blind review lane: security pass, code-review blocker (Enter on chip ✕) fixed, verifier pass. Quick gate + changed-area suites green; visual check done at 1280/390px (clean). PR #7454 merged by the lane; Jaah Deploy succeeded. Deferred: legacy NodeLink alias mount retirement; api docstring prose pass. Memory: none applied; proposed 0.