Rename Go module paths to repo.anhonesthost.net/CyberCoveLLC/threshold

Rename root, api and sdk module paths (imports, go.mod, go_package,
ldflags, build scripts, buf configs) and regenerate protobuf/gateway
code with the project's pinned toolchain. Wire identifiers unchanged.
api gets a local replace for sdk; root/api/sdk require v0.1.0.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/plugin/loopback/testing_grpc_stream.go

@@ -9,7 +9,7 @@ import (
 	"io"
 	"sync"
 
-	plgpb "github.com/hashicorp/boundary/sdk/pbs/plugin"
+	plgpb "repo.anhonesthost.net/CyberCoveLLC/threshold/sdk/pbs/plugin"
 	"google.golang.org/grpc/metadata"
 )