Tenant-scoped fallback ticket model for accounts without PSA integration.
Tracks customer-name, problem-statement, status lifecycle (open/walking/
resolved/escalated), and optional links to flow/proposal/ai_session/
assigned engineer + PSA promotion ID. Account-scoped RLS policy uses
app.current_account_id session setting.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
