Top five code reduction opportunities implementation

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 code-reduction cuts: deleted 5 test-only web exports + 7 never-passed props (−124), one useWindowDrag hook, one AWS tag builder, two helper homes; three folds built and reverted as net-positive. Net −156 lines. Quick gate, tsc, 1165 web + 77 API tests green; divider drag verified live. PR #7606 queued to the merge lane (deploy watch deferred to the lane). Large levers are ADR-backed product decisions, sized in the report.