Implement Top 5 Code Reduction 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 :)

Implemented the five largest LOC cuts left: shared web auth-mock (81 suites), API tests on seed builders, console + Python clones single-homed, one Pydantic base. Net −895 lines/123 files. Full gate green; PR #5464 merged (505c91ac3); Jaah Deploy success. Visual check done, surfaces unchanged. No multi-thousand-line cut remains ungated (SKYNET shims, _legacy_* columns deferred). UI nits + a second auth helper named as follow-ups.