Audit and consolidate documentation architecture

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

Context-architecture audit found no stale or duplicate docs: gate green, no active specs or trackers, all ADR citations resolve, the 9 uncited ADRs still match code, no history narration. No change, no PR.