Clean and organize all documentation systematically

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

Audited docs with the context-architecture playbook: Tier-1 check and selftest pass, no trackers/active specs, ADR register current (homes exist), no duplicates or history narration. No edits needed; no PR.