wasteNot: wastenot_candidates table in v2.sqlite + verdict write path

Add table wastenot_candidates to v2.sqlite: id, msg_id, ts, sender, recipient, reason, model, unnecessaryCandidate INT default 1, opinion_sender, opinion_recipient, opinion_ts, verdict (agree/disagree/needs-elazar), verdict_by, verdict_ts, pattern. Plus a write path monitor-llmmsgsrv-cc may use for verdict (hub endpoint or a CLI in your lane) - monitor cannot write v2.sqlite. Rule: opinion asks must not fan; one DM per party.