Identify and implement top five 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 :)

No PR: a six-axis census (jscpd, Python+TS AST clones, importer/export census, vulture cross-check) finds the tree at its code-reduction floor. The five largest remaining folds (~400/120/70/60/30 lines) each need an owner decision; ranked in the report. Memory confirmed + 1 qa unit proposed.