Scrub Documentation and Route via CLAUDE.md

Use context architecture skill to scrub all old documentation, including instructions, specs, trackers, ADRs - delete everything superseeded and stale, remove references to historical decisions, delete duplicates, single home everything and make sure all documentation is accessible from CLAUDE.md router in a few steps

Docs scrub merged (PR #5750): removed dated benchmark/task-number provenance from lifecycle and test-perf docs; rest audited already current-state. Benchmarking doc edit deferred (PR #5735 owns it). Deploy watch unverified (docs-only).