The settings UI description for the 'balanced' profile said 'Opus for
planning, Sonnet for execution/verification' — omitting that research
also uses Sonnet. Users assumed research was included in 'planning'
and expected Opus for the researcher agent.
Updated to: 'Opus for planning, Sonnet for research/execution/verification'
This matches model-profiles.md and the actual MODEL_PROFILES mapping.
Fixes#680