Consolidate and Clean Up 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

Audited docs against the context-architecture rules: checker passes, no stale/historical/duplicate/orphan content, ADR citations all resolve, every doc reachable from CLAUDE.md in ≤2 hops. Nothing to delete; no PR. Memory: none applied.