When a new voice session starts and the customer already has a trusted
display_name on file (e.g. from a previous call), automatically set
name_status to 'name_obtained' so the AI greets them by name instead
of asking again.
- Block old _voice_downstream_name_update from overwriting name_obtained status
unless user explicitly says 'меня зовут X' (explicit_candidate only)
- Move _persist_voice_name_state to run AFTER LLM extraction, not before,
so LLM always gets a chance to override the regex result
- Fixes bug where phrases like 'можешь назвать их' were incorrectly
captured as customer name, overwriting the real name
Yera All