refactor: replace Yonexus.Client dependency with Protocol crypto

Server no longer needs Yonexus.Client at build or runtime.
verifySignature, generateKeyPair, signMessage now imported from Protocol.

plugin/core/runtime.ts

@@ -38,7 +38,7 @@ import {
   type ClientRecord,
   type ServerRegistry
 } from "./persistence.js";
-import { verifySignature } from "../../../Yonexus.Client/plugin/crypto/keypair.js";
+import { verifySignature } from "../../../Yonexus.Protocol/src/crypto.js";
 import type { YonexusServerStore } from "./store.js";
 import { type ClientConnection, type ServerTransport } from "./transport.js";
 import { createPairingService, type PairingService } from "../services/pairing.js";

tests/auth-failures.test.ts

@@ -10,7 +10,7 @@ import { createYonexusServerRuntime } from "../plugin/core/runtime.js";
 import type { ClientRecord } from "../plugin/core/persistence.js";
 import type { YonexusServerStore } from "../plugin/core/store.js";
 import type { ClientConnection, ServerTransport } from "../plugin/core/transport.js";
-import { generateKeyPair, signMessage } from "../../Yonexus.Client/plugin/crypto/keypair.js";
+import { generateKeyPair, signMessage } from "../../Yonexus.Protocol/src/crypto.js";
 
 function createMockSocket() {
   return { close: vi.fn() } as unknown as ClientConnection["ws"];

tests/runtime-flow.test.ts

@@ -17,7 +17,7 @@ import { createYonexusServerRuntime } from "../plugin/core/runtime.js";
 import type { ClientRecord } from "../plugin/core/persistence.js";
 import type { YonexusServerStore } from "../plugin/core/store.js";
 import type { ClientConnection, ServerTransport } from "../plugin/core/transport.js";
-import { generateKeyPair, signMessage, verifySignature } from "../../Yonexus.Client/plugin/crypto/keypair.js";
+import { generateKeyPair, signMessage, verifySignature } from "../../Yonexus.Protocol/src/crypto.js";
 
 function createMockSocket() {
   return {