Generalize EchoAggregation to monoid/group form (#175); CC-BY-SA-4.0 prose; 2026-06-19 AFFIRMATION + status #452

Job	Run time
governance / Well-Known (RFC 9116 + RSR)	3s
governance / Workflow security linter	35s
governance / Code quality + docs	39s
governance / Language / package anti-pattern policy	9s
governance / Trusted-base reduction policy	39s
governance / Licence consistency	30s
governance / Guix primary / Nix fallback policy	33s
governance / Security policy checks	3s
governance / Validate Hypatia baseline	4s
	3m 15s

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