feat(client): add keypair generation

plugin/core/runtime.ts

@@ -9,11 +9,12 @@ import {
 } from "../../../Yonexus.Protocol/src/index.js";
 import type { YonexusClientConfig } from "./config.js";
 import {
-  createInitialClientState,
+  ensureClientKeyPair,
   hasClientKeyPair,
   hasClientSecret,
-  type YonexusClientState,
-  type YonexusClientStateStore
+  createInitialClientState,
+  YonexusClientState,
+  YonexusClientStateStore
 } from "./state.js";
 import type { ClientConnectionState, ClientTransport } from "./transport.js";
 
@@ -66,7 +67,12 @@ export class YonexusClientRuntime {
     }
 
     this.phase = "starting";
-    this.clientState = await this.options.stateStore.load(this.options.config.identifier);
+    
+    // Load existing state and ensure key pair exists
+    let state = await this.options.stateStore.load(this.options.config.identifier);
+    const keyResult = await ensureClientKeyPair(state, this.options.stateStore);
+    this.clientState = keyResult.state;
+    
     await this.options.transport.connect();
   }
 

plugin/core/state.ts

@@ -1,5 +1,6 @@
 import { mkdir, readFile, rename, writeFile } from "node:fs/promises";
 import { dirname } from "node:path";
+import { generateKeyPair, type KeyPair } from "../crypto/keypair.js";
 
 export const CLIENT_STATE_VERSION = 1;
 
@@ -132,6 +133,31 @@ export function hasClientKeyPair(state: YonexusClientState): boolean {
   );
 }
 
+/**
+ * Ensure the client state has a valid key pair.
+ * If no key pair exists, generates a new Ed25519 key pair.
+ * Returns the (possibly updated) state and whether a new key was generated.
+ */
+export async function ensureClientKeyPair(
+  state: YonexusClientState,
+  stateStore: YonexusClientStateStore
+): Promise<{ state: YonexusClientState; generated: boolean }> {
+  if (hasClientKeyPair(state)) {
+    return { state, generated: false };
+  }
+
+  const keyPair = await generateKeyPair();
+  const updatedState: YonexusClientState = {
+    ...state,
+    privateKey: keyPair.privateKey,
+    publicKey: keyPair.publicKey,
+    updatedAt: Math.floor(Date.now() / 1000)
+  };
+
+  await stateStore.save(updatedState);
+  return { state: updatedState, generated: true };
+}
+
 function assertClientStateShape(
   value: unknown,
   filePath: string