Implementação v2.0

• schema 8 e migrations 6/7→8;
• modules/copilot_v2: contracts, repository, state/NBA, tools e approval service;
• /api/v2: career state, evidence/edges, portfolio, approvals, plans, tools, context, audit, search;
• frontend: Career Cockpit, Evidence Inbox, Portfólio, Approval Queue, drawer e Ctrl/Cmd+K;
• segurança: schema estrito, forbidden tools, stale/expiry/idempotency, audit e undo;
• documentação, assets, packaging e gate de release.