feat: export realms from client

Signed-off-by: Alano Terblanche <18033717+Benehiko@users.noreply.github.com>

Author: Benehiko

client/realms/docker.go

@@ -0,0 +1,69 @@
+// Package realms exposes the canonical set of Docker realm patterns that
+// clients use to scope secret queries.
+//
+// A realm is a path-pattern contract - not a permission boundary. Clients use
+// realms to declare which set of secrets they care about (e.g. Hub auth,
+// registry auth, MCP OAuth). Once a realm is established its pattern MUST NOT
+// change; clients may pin to a realm and treat it as a stable interface.
+//
+// The Docker realm hierarchy is:
+//
+//	docker/                        – all Docker secrets
+//	docker/auth/hub/**             – Docker Hub authentication (OAuth login)
+//	docker/auth/hub-staging/**     – Docker Hub staging authentication
+//	docker/auth/registry/docker/** – Docker Registry authentication
+//	docker/auth/metadata/hub/**    – metadata for the default Hub user
+//	docker/mcp/**                  – MCP-related secrets
+//	docker/mcp/oauth/**            – MCP OAuth credentials
+//	docker/mcp/oauth-dcr/**        – MCP Dynamic Client Registration configs
+//	docker/sandbox/**              – Sandbox-related secrets
+//	docker/sandbox/oauth/**        – Sandbox third-party OAuth tokens
+//
+// All variables in this package are re-exported from
+// github.com/docker/secrets-engine/x/realms and are provided here as a
+// stable, versioned surface for external consumers.
+package realms
+
+import xrealms "github.com/docker/secrets-engine/x/realms"
+
+// Docker realms all start with `docker/` as the prefix.
+//
+// Authentication flows done by the Docker CLI, Docker Desktop and Docker related
+// products must go through `docker/auth`.
+//
+// Docker Hub authentication (browser based OAuth login) will be prefixed
+// with `docker/auth/hub/<username>`.
+//
+// Docker Registry authentication will be prefixed with
+// `docker/auth/registry/docker/<username>`.
+var (
+	DockerHubAuthentication             = xrealms.DockerHubAuthentication
+	DockerHubStagingAuthentication      = xrealms.DockerHubStagingAuthentication
+	DockerRegistryAuthentication        = xrealms.DockerRegistryAuthentication
+	DockerRegistryStagingAuthentication = xrealms.DockerRegistryStagingAuthentication
+)
+
+var (
+	// DockerHubAuthenticationMetadata is a pointer to the default user signed in to Docker
+	DockerHubAuthenticationMetadata = xrealms.DockerHubAuthenticationMetadata
+	// DockerHubStagingAuthenticationMetadata is a pointer to the default staging user signed in to Docker
+	DockerHubStagingAuthenticationMetadata = xrealms.DockerHubStagingAuthenticationMetadata
+)
+
+var (
+	// DockerMCPDefault is the default realm used for MCP related secrets
+	DockerMCPDefault = xrealms.DockerMCPDefault
+	// DockerMCPOAuth is the realm used for all MCP OAuth credentials retrieved by Docker.
+	DockerMCPOAuth = xrealms.DockerMCPOAuth
+	// DockerMCPOAuthDCR is the realm used to hold Dynamic Client Registered (DCR)
+	// OAuth configurations for supported MCP servers.
+	DockerMCPOAuthDCR = xrealms.DockerMCPOAuthDCR
+)
+
+var (
+	// DockerSandbox is the default realm used for Sandbox related secrets
+	DockerSandbox = xrealms.DockerSandbox
+	// DockerSandboxOAuth is the realm used for all Sandbox OAuth credentials
+	// such as third-party tokens - this does not store the Docker Auth tokens.
+	DockerSandboxOAuth = xrealms.DockerSandboxOAuth
+)