Reduce repository code through refactoring 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 :)

Five code reductions shipped in PR #6856 (61 files, +517/−1047): plan switches generated from the registry, one org-admin gate and route scaffolding home, clock.as_utc everywhere, dead load script and vite plugin deleted, web helpers single-homed. Quick gate and changed-area tests green; review lanes pass; visual check done, all surfaces render as before. "Massively" not reachable: repo already deduplicated; the 192k-line vendored SDK bundle is deliberate (ADR-0159) and kept. PR queued in the merge lane. Memory: used mem-25288, mem-23434; proposed 1 gotcha.