Evidence and handoff

Prove the intended behavior

Use the verification levels without inventing a stronger adjective. A successful build is not a behavior test; emulator evidence is not physical-hardware evidence.

For a new guard, mutate the exact condition named by the guard, prove the mutation built and the test ran, observe the named failure, restore the source, and observe the pass. A build failure, a different mutation, or a green test that reached no machine is not mutation evidence.

For emulator or hardware work, preserve the build identity, machine identity, lane/port, base image, staged artifacts, and guest-reported capabilities. The stored artifact must prove an observation plane armed; an invocation log does not.

Close the task coherently

Before handing off:

1. run the relevant gate and record skips;
2. update the public behavior page and docs/open-issues.md when the arc changes what is known, broken, or unverified;
3. rederive every declared document whose source moved;
4. commit a coherent checkpoint on the task branch;
5. confirm the worktree contains no unreported task changes.

Report both the technical diff and the semantic result: what a person or developer can do or understand now, why the boundary changed, what was tested, what remains uncertain, and the next natural integration step. Do not use a generic “works” closeout.