# Shared infrastructure diagnostics

This package contains harness-owned fixtures, not participant model policies.
`constant.py` returns a supplied fixed action chunk through the same `Policy`
interface used by real methods. It performs no model inference and does not
plan actions from observations. Its descriptor labels every run
`infrastructure_validation_only`.

The CLI name remains `--policy constant`; action validation, chunk length and
execution budgets are unchanged. Using this policy with a native adapter can
move the robot or simulator, so only run it as an explicitly authorized
diagnostic with valid actions and environment safety checks. It is not a task
capability score or a named-model baseline.

Shared diagnostics are included in new `harness_source/` snapshots. Old frozen
campaigns and their recorded source inventories retain their original bytes;
there is no `AgentPolicies.diagnostics` compatibility shim in the current source.

`robot_state_hold.py` is an explicit one-control SIM-only sensor/target wiring
check. The operator must first confirm that the identically named public sensor
and action fields mean absolute robot targets in the same units and frame. It
echoes that state once through the ordinary authenticated SIM server client,
not through a private simulator handle. The server must declare
`diagnostic=true`, and `--confirm-absolute-state-targets` is mandatory. It does
not infer a task action or guarantee physical holding, and must never be used
on real hardware. Its one fixture decision has zero model requests and is not
a capability score. Keep these artifacts separate from scored model attempts.

Native asset, rendering, reset and control readiness tools belong under the
corresponding benchmark's `benchmarks/.../environment/`. Participant policy
behavior belongs under `AgentPolicies/<profile>/`.

CPU-only checks for this package:

```sh
python -B -m unittest benchkit.checks.test_diagnostics -v
```

`simpler_mailbox.py` retains the fixed seven-zero-action mailbox-v2 diagnostic
formerly under SimplerEnv's environment directory. It is an explicitly selected
historical transport fixture, not a model or a general robot-safe action. It
requires matching v2 / decision-budget settings; it does not support the current
v3 mailbox by implication. Do not use it on real hardware or count it as a score.