Migrate ReferencingServers to ReferencingWorkloads on remaining CRDs

[ChrisJBurns]

Summary

RFC-0023 specifies a structured referencingWorkloads list with kind and name fields on shared configuration CRD status, rather than plain []string. PR #4483 migrated MCPOIDCConfig to the new WorkloadReference type. The same migration is needed for the remaining three CRDs.

CRDs to migrate

CRD	File	Current field
MCPToolConfig	cmd/thv-operator/api/v1alpha1/toolconfig_types.go:80-83	ReferencingServers []string
MCPExternalAuthConfig	cmd/thv-operator/api/v1alpha1/mcpexternalauthconfig_types.go:715-718	ReferencingServers []string
MCPTelemetryConfig	cmd/thv-operator/api/v1alpha1/mcptelemetryconfig_types.go:62-64	ReferencingServers []string

Target state

Each CRD should use the WorkloadReference type (already defined in mcpoidcconfig_types.go):

type WorkloadReference struct {
    Kind string `json:"kind"` // MCPServer, VirtualMCPServer, MCPRemoteProxy
    Name string `json:"name"`
}

Field rename: ReferencingServers []string → ReferencingWorkloads []WorkloadReference

Controllers to update

For each CRD, the corresponding controller builds and compares the referencing list:

• ToolConfigReconciler (toolconfig_controller.go) — updateReferencingServers() method
• MCPExternalAuthConfigReconciler (mcpexternalauthconfig_controller.go) — updateReferencingServers() method
• MCPTelemetryConfigReconciler — equivalent method

Each needs to build WorkloadReference structs with explicit Kind instead of plain server name strings.

Pattern to follow

See the MCPOIDCConfig migration in PR #4483 for the exact pattern:

• findReferencingServers → findReferencingWorkloads returning []WorkloadReference
• Watch handlers compare ref.Kind == "MCPServer" && ref.Name == server.Name instead of ref == server.Name
• Deletion protection message uses "ReferencedByWorkloads" reason

Notes

• This is a breaking change to the CRD status schema (status fields are not part of the API contract for clients, but tooling that reads status will need updates)
• The WorkloadReference type is shared — defined once in mcpoidcconfig_types.go, reusable by all CRDs
• CRD manifests, deepcopy, and API docs need regeneration after the change