Premium/enhanced voices ship with the tier in their name (e.g. "Ava
(Premium)"), so appending "— Premium" produced "Ava (Premium) — Premium"
in the voice picker. Move the label logic to SpeechSettings.displayLabel
and skip the suffix when the name already contains the tier (still
name-only for default voices). Deterministic string helper, unit-tested.
Claude-Session: https://claude.ai/code/session_01BQcEWmAPA78338QuEwRkAh