Surface a failed-turn strip when a model cannot resolve

[TheGreatAxios]

Messaging an agent whose model cannot resolve is now a failed turn with recovery, never a raw HTTP 500.

What changed

• Wake and mint wrap InferenceResolutionError as a named consumer error.
• POST /workbenches and other on-request mint paths return 409 not_launchable with consumer copy instead of 500.
• Uncaught InferenceResolutionError maps through hub onError to 422 with the same copy.
• The failed-turn strip names the agent, offers 2-4 tenant chat models, applies the pick, retries the turn, and hops to that agent's Settings.

Tests

• Wake/sendMail resolution failure does not 500 and does not write the raw dump onto the turn.
• Strip copy, picker, apply+retry, and Settings hop.

Closes CL-6491