sync-architecture

Post-implementation documentation-sync detector. Spins up ONE read-only subagent on a completed task's diff to find everything the change introduced that the architecture docs don't yet know about — new endpoints, patterns, dependencies, domain terms, ADR-worthy decisions — routed to the exact doc each belongs in. Autonomous runs apply only append-only safe additions and defer domain/ADR reshapes; interactive runs present the proposed doc deltas to pick. Use after a task's missions are done (from create-task / start-task / start-roadmap) or standalone on a diff.