fusion/.changeset/fn-4948-precommit-branch-identity-guard.md

@runfusion/fusion

@runfusion/fusion
patch

Prevent cross-branch commit contamination at the source: every task worktree now installs a pre-commit hook that refuses commits when HEAD does not match the worktree's owning task branch (with an allowlist for parallel-step branches). As defense-in-depth, contamination auto-recovery now drops obviously-misrouted foreign commits whose task-id attribution and changed-path namespace unambiguously belong to another task (initial heuristic: .changeset/fn-<that-id>-*), instead of escalating them to human adjudication.