fix: fail expired monitor desktop leases

server/migrations/20260623103000_add_monitor_task_lease_recovery_index.down.sql

@@ -0,0 +1 @@
+DROP INDEX CONCURRENTLY IF EXISTS idx_desktop_tasks_monitor_lease_recovery;

server/migrations/20260623103000_add_monitor_task_lease_recovery_index.up.sql

@@ -0,0 +1,6 @@
+CREATE INDEX CONCURRENTLY IF NOT EXISTS idx_desktop_tasks_monitor_lease_recovery
+    ON desktop_tasks (lease_expires_at ASC, updated_at ASC, desktop_id ASC)
+    WHERE kind = 'monitor'
+      AND status = 'in_progress'
+      AND monitor_task_id IS NOT NULL
+      AND lease_expires_at IS NOT NULL;