The agent's name plus any aliases to match (e.g. ['Sage', 'the assistant']).
Each is matched as a whole word/phrase, case-insensitively. Empty/blank names are ignored.
The transcript segment to test.
true if the agent was addressed in the segment.
A default name/mention matcher: the agent is "addressed" when the segment text contains one of the agent's names/aliases as a whole word (case-insensitive). Human-only segments are eligible; agent-spoken segments are never treated as addressing the agent (avoids self-trigger loops).