MariaDB provider gets the pod scheduling editor

Placing MariaDB pods is now part of the instance form. In the MariaDB provider v0.1.7, the old free-text Node targeting field is replaced by a Pod scheduling policy section under Advanced. It uses the scheduling editor that shipped in OpenEverest v2.0.0-dev.4. From there you can pin MariaDB to a node pool, tolerate its taints, and spread replicas across nodes or zones.

The engine’s schedulingPolicy now reaches the MariaDB resource in full. Before this release, the API accepted nodeSelector, tolerations and topologySpreadConstraints but the provider silently dropped them. The MaxScale proxy takes its own schedulingPolicy through the API.

Two behaviour changes come with it. The nodeAffinity engine parameter is removed, so move those rules to spec.components.engine.schedulingPolicy.affinity.nodeAffinity. And on HA topologies, any affinity you set now replaces the default soft anti-affinity instead of being merged into it; affinity: {} means no constraints at all. The details are in provider-mariadb#86.