Reduce codebase size by implementing five refactoring

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 :)

Surveyed the whole tree for LOC cuts (clone rate 0.04% prod / 0.03% tests, 0 dead web/tools modules); implemented 4 safe cuts (dead CLI + gate stage, 31 unreferenced constants, 18 test-only functions, 2 helper folds) net −660 lines, named the 5 fleet-gated pools (~1,950 lines) with unlocks. Blind code+security+verifier lanes pass. PR #7007 queued to the merge lane. Memory: used mem-25697; proposed none.