0.65.0-alpha · core 2026-09-19

Parallel safety rails and scope measurement. The actionable core of the structured-parallel RFC, without narrowing existing capability: cymbal transitive-disjointness check before parallel dispatch (target_files intersection stays the fallback floor), parent-owned test-gated merge (workers never negotiate merges), regression baseline captured pre-change and compared at close-out as blocking gaps, and a measurement mirror per scope (started_at, finished_at, duration_s, baseline, host-reported cost — never estimated). Worktree mode documented: isolation replaces locking, merge + test gate stay. Reviewer-independence guidance in Verification.

sync-scopes refuses blockedBy cycles at ingest (exit 1, names the a -> b -> a path, no state written) and warns on dangling references — a cycle used to stall execution silently with each scope waiting on the other forever.