v0.2.5

Smith v0.2.5

Smith 0.2.5 shows the model, not just the operator, why a sub-agent failed.

Fixed: the agent tool reports a failed child's reason

v0.2.3 gave a failed child's cause to the parent, and the TUI and the session
journal have shown it since. The agent tool did not: it rendered the child's
status snapshot, which carried state: failed and nothing about why. That is
the one reader whose next action depends on the answer, and a failure with no
reason attached reads as one worth retrying.

The runtime now records the cause on the child's status, and the tool result
carries it:

{
  "child_id": "child-1",
  "state": "failed",
  "error": "child turn failed: Gemini provider rejected the request: Input
            blocked: the prompt contains sensitive words that violate
            Google's Generative AI Prohibited Use policy.",
  "tokens_used": 0
}

The field is absent rather than null when a child has not failed, and it is
cleared when a child starts a later task, so it always describes the state the
child is in.

Upgrading

Existing configuration, sessions, and protected checkpoints remain compatible.
The pinned Agent Runtime revision advances to 7c6ae53.

Full Changelog: v0.2.4...v0.2.5