Log every admin-panel action (user activate/deactivate, team BYOC toggle,
team delete, template delete, build create/cancel) to the audit_logs table
under PlatformTeamID with scope "admin".
Add GET /v1/admin/audit-logs endpoint and /admin/audit frontend page with
infinite scroll and hierarchical filters. Expose audit.Entry + Log() for
cloud repo extensibility.
Fix seed_platform_team down-migration FK violation by deleting dependent
rows before the team row.