Identify and implement five major 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 :)

Folded the six largest exact-duplicate blocks left (all in tests) into one helper each, net -112 lines; quick gate pass, api 206 / vitest 303 / portfolio 291 green; PR #7862 queued to the merge lane. Measured floor documented: no massive mass remains; older-node compat (needs cp census, credential refused) and GET /api/telemetry/runs (deprecation decision) deferred. Memory: used mem-25288, mem-35380; flagged mem-35895; proposed 0. No UI surface affected.