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 :)

Measured the repo (jscpd + window scan: 0.03–0.3% duplication, no dead files/routes) and implemented the five largest real cuts: ACP replay harness, web org/signup/desk/Stripe fixtures, API login sandbox + silent catalogue + four recorders, jaahd FakeHttpResponse + in-file twins, accounts.py lock/readback/reader folds. Net −135 lines, 55 files, no assertion or behaviour changed. Quick gate green, 1,683+ changed-area tests green, blind code/security review + verifier pass (evidence comment on PR). PR #7096 queued to the merge lane; deploy watch is the lane's post-merge step. PR 7085's files avoided. Deferred (product calls): StateBadge→StatusChip, D5 alias layer, LegacyRedirects, legacy_project_id. Memory: used mem-27643; proposed 0.