Identify and implement five 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 :)

Implemented the 5 best-evidenced code reductions: one Pager (KeysetPager folded), one Mono (4 local copies), StatusChip derives tone colour, dead PHONE_ACTIONS_CELL_RULE removed, Jira Retry-After via http_bounded. Net −37 lines. Quick gate + 440 vitest + 81 pytest green; PR #7074 queued in the lane. Named: repo-wide shingle/dead-code scans show no larger deletable mass without removing live compat; "massively" not reachable.