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 :)

Implemented the top 5 code reductions (FormTextField unification in 19 files, retiring-columns contraction migration, test-value audit, test dedup, last exact clones): net about -400 lines. Review lane found and fixed the empty-start native-select trap at 5 sites. Quick gate + 1882 API / 1396 web / 83 jaahd tests green; visual check done on 4 surfaces, all clean. PR #7387 queued to the merge lane. Memory: used none; proposed 1 gotcha this session (3 for the task).