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 :)

Five copy families collapsed, net −225 lines (66 files): web test provider stacks → themeRender, API test helpers → conftest/seed, slug triple → unique_org_slug, get_text, shq/GroupMember. Full gate green ×2, 3 review lanes pass, PR #5401 merged, Jaah Deploy success. Deferred: 14 unwired tools/tests (2 bit-rotted, Windows O_NOFOLLOW bug). mem-15536 shaped scope.