Make hosted voice voicemail setting explicit

[dimavrem22]

Executive Summary

This PR makes the hosted voice live test request its asserted voicemail-detection setting explicitly.

• Requests disabled voicemail detection in the model-facing call instruction.
• Keeps the runtime call configuration and tool contract unchanged.

Description

The hosted outbound voice fixture now tells OpenCode to set voicemailDetection to disabled when placing the call. This aligns the model-controlled tool input with the persisted-call assertion before the test exercises post-call SMS settlement.

Reason

The optional per-call setting could otherwise vary with model tool arguments and fail the live test before it reached the behavior under test.

Decisions

• Runtime scope: Kept the per-call override unchanged because the nondeterminism belongs to the test request, not the public calling contract.

Testing

• npm test: 65 files and 799 tests pass.
• npm run lint: passes.
• npm run typecheck: passes.
• npm run build: passes.
• Hosted outbound voice CI: Expected to persist voicemailDetection=disabled and continue through exact post-call SMS settlement.