feat(busvectors): add nkey + signed control-request vectors

Extend the cross-language vectors with the NATS user nkey derived from the
Ed25519 public key, and a signed control-plane request (CanonicalRequest +
Ed25519 signature). These let the TypeScript busauth port verify it authenticates
on both planes exactly like the Go client (issue uniweb/0001, Phase 1).

cmd/busvectors/main.go

@@ -35,7 +35,9 @@ import (
 
 	cs "fn-registry/functions/cybersecurity"
 
+	"github.com/enmanuel/unibus/pkg/busauth"
 	"github.com/enmanuel/unibus/pkg/frame"
+	"github.com/enmanuel/unibus/pkg/membership"
 	"golang.org/x/crypto/chacha20poly1305"
 	"golang.org/x/crypto/curve25519"
 )
@@ -58,12 +60,14 @@ var (
 // is hex except the frame wire bytes, which are base64 (the frame is JSON, so the
 // TS side compares the exact UTF-8 bytes).
 type vectors struct {
-	Note     string         `json:"note"`
+	Note     string             `json:"note"`
-	Endpoint endpointVector `json:"endpoint_id"`
+	Endpoint endpointVector     `json:"endpoint_id"`
-	Sign     signVector     `json:"sign"`
+	Nkey     nkeyVector         `json:"nkey"`
-	AEAD     aeadVector     `json:"aead"`
+	Sign     signVector         `json:"sign"`
-	KeyBox   keyboxVector   `json:"keybox"`
+	AEAD     aeadVector         `json:"aead"`
-	Frame    frameVector    `json:"frame"`
+	KeyBox   keyboxVector       `json:"keybox"`
+	Frame    frameVector        `json:"frame"`
+	CtrlReq  controlReqVector   `json:"control_request"`
 }
 
 type endpointVector struct {
@@ -71,6 +75,22 @@ type endpointVector struct {
 	EndpointID string `json:"endpoint_id"` // base64url(sha256(sign_pub)), unpadded
 }
 
+type nkeyVector struct {
+	SignPubHex string `json:"sign_pub_hex"`
+	NkeyPublic string `json:"nkey_public"` // NATS user nkey ("U...") from the Ed25519 pubkey
+}
+
+type controlReqVector struct {
+	Method       string `json:"method"`
+	Path         string `json:"path"`
+	Ts           string `json:"ts"`
+	Nonce        string `json:"nonce"`
+	BodyHex      string `json:"body_hex"`       // raw request body (empty for GET)
+	CanonicalHex string `json:"canonical_hex"`  // bytes that get signed
+	SigHex       string `json:"sig_hex"`        // Ed25519 over canonical, by the signer below
+	SignPrivHex  string `json:"sign_priv_hex"`
+}
+
 type signVector struct {
 	SignPrivHex string `json:"sign_priv_hex"`
 	SignPubHex  string `json:"sign_pub_hex"`
@@ -171,6 +191,24 @@ func run(out *os.File) error {
 		return fmt.Errorf("marshal frame: %w", err)
 	}
 
+	// NATS user nkey derived from the Ed25519 public key (the browser must produce
+	// the same "U..." string to authenticate on the data plane).
+	nkeyPub, err := busauth.NkeyPublicFromSignPub(signPub)
+	if err != nil {
+		return fmt.Errorf("nkey public: %w", err)
+	}
+
+	// A signed control-plane request vector: the browser signs CanonicalRequest the
+	// same way to authenticate every HTTP call to membershipd. A POST with a body
+	// exercises the sha256(body) term.
+	const ctrlMethod = "POST"
+	const ctrlPath = "/rooms"
+	const ctrlTs = "1700000000"
+	const ctrlNonce = "Zm9vYmFyMTIzNDU2Nzg5MA=="
+	ctrlBody := []byte(`{"subject":"room.parity"}`)
+	canonical := membership.CanonicalRequest(ctrlMethod, ctrlPath, ctrlTs, ctrlNonce, ctrlBody)
+	ctrlSig := ed25519.Sign(signPriv, canonical)
+
 	v := vectors{
 		Note: "Deterministic cross-language vectors for the unibus protocol. Generated by " +
 			"cmd/busvectors in the unibus repo; regenerate with `go run ./cmd/busvectors`. " +
@@ -179,6 +217,10 @@ func run(out *os.File) error {
 			SignPubHex: hex.EncodeToString(signPub),
 			EndpointID: frame.EndpointID(signPub),
 		},
+		Nkey: nkeyVector{
+			SignPubHex: hex.EncodeToString(signPub),
+			NkeyPublic: nkeyPub,
+		},
 		Sign: signVector{
 			SignPrivHex: hex.EncodeToString(signPriv),
 			SignPubHex:  hex.EncodeToString(signPub),
@@ -210,6 +252,16 @@ func run(out *os.File) error {
 			SigningB64: base64.StdEncoding.EncodeToString(f.SigningBytes()),
 			SigHex:     hex.EncodeToString(f.Sig),
 		},
+		CtrlReq: controlReqVector{
+			Method:       ctrlMethod,
+			Path:         ctrlPath,
+			Ts:           ctrlTs,
+			Nonce:        ctrlNonce,
+			BodyHex:      hex.EncodeToString(ctrlBody),
+			CanonicalHex: hex.EncodeToString(canonical),
+			SigHex:       hex.EncodeToString(ctrlSig),
+			SignPrivHex:  hex.EncodeToString(signPriv),
+		},
 		// kexPub is unused in a vector field today but derived above to validate the
 		// scalar; reference it so the intent is documented.
 	}