Add USB policy improvements and emprestimos details modal

- Add cron job to cleanup stale pending USB policies every 30 min
- Add cleanupStalePendingPolicies mutation to usbPolicy.ts
- Add USB policy fields to machines listByTenant query
- Display USB status chip in device details and bulk control modal
- Add details modal for emprestimos with all loan information
- Add observacoesDevolucao field to preserve original observations
- Fix status text size in details modal title

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

convex/machines.ts

@@ -1015,6 +1015,9 @@ export const listByTenant = query({
           lastPostureAt,
           remoteAccess: machine.remoteAccess ?? null,
           customFields: machine.customFields ?? [],
+          usbPolicy: machine.usbPolicy ?? null,
+          usbPolicyStatus: machine.usbPolicyStatus ?? null,
+          usbPolicyError: machine.usbPolicyError ?? null,
         }
       })
     )