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 :)

Top 5 found with repo-wide detectors; 3 shipped (billing Telegram fan-out folded into email_notify; authz.require_org_key/require_org_admin + project_of_task replace 6 copies; one Intl.NumberFormat home), production −22 lines. 2 dropped on measurement (audit Absent +2; test sweep: 0 of 60 deletable). Repo has no large dup/dead block (jscpd 0%, 0 unreferenced funcs). Legacy retirements deferred: cp DB tunnel refused. Security lane pass. PR #7557 queued in the merge lane. Visual check: no UI appearance change. Memory: used mem-32217; proposed 1 gotcha.