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 :)

Five code-volume cuts, net −2,304 lines over 186 files: 330 API routes folded onto @on_session (db_async), 15 Patch models onto partial_of, test seed wrappers onto seed makers, gh-pr guard parsing onto git_command, RegistryPage/security sections/EfficiencyTab onto ui/ homes. Quick gate and every changed-area suite green; blind code-review/security/verifier lanes pass after one fix commit; visual check done (registry desktop+phone good; Efficiency rows need analytics the slot lacks). PR #7831 queued to the merge lane. Deferred: 59 refused route pairs, jaah_cli copies (packaging). Memory: used mem-25288, mem-22590, mem-31277; proposed none.