[mlaccetti]

Completed tasks have been leaving reproducible build outputs and linked worktrees behind; individual iOS build directories can grow to roughly 8 GiB. Add a completion cleanup step to the worker and coordinator policies.

Workers retain dependencies and build outputs still needed for integration, verification, or hooks. Coordinators clean disposable task outputs when verification, hooks, and delivery no longer need them, preserve open-PR source worktrees, and require exact merge proof plus fresh activity/status checks before worktree removal. Ignored files receive a file-level inventory so local configuration and evidence cannot disappear behind a clean ordinary Git status. Shared caches and Docker data remain separate explicitly scoped cleanup tasks.

Validation: mise exec -- go test ./kit and git diff --check passed. An independent adversarial review identified the collapsed ignored-directory inventory issue; the final policy uses file-level enumeration. This changes policy templates; it relies on the native harness lifecycle rather than a scheduled cleanup service.