The deploy form's cluster dropdown fetched every visible cluster, so
clusters configured for GPU-service (k8s_options.gpu_instance_options
set) showed up as deployable targets even though deployments cannot
run on them.
Pass gpu_instance_enabled=false on the cluster-list query so the
backend returns only model-deployment clusters. GPU-instance creation
does not pick a cluster directly (it is derived from the instance
type), so no symmetric change is needed there.
Add the organization picker to the model deployment and model-file
download forms (platform-admin "all organizations" view). Filter the
cluster / worker pickers to clusters the chosen org owns, so the created
resource's owner stays aligned with where it runs and a cross-org cluster
can't be selected. Carry owner ids on the cluster / worker options to
drive the filter.
