feat: add session.list and session.history invoke handlers (real workspaces/messages)

lib/index.js

@@ -106,12 +106,35 @@ function apply(ctx, config) {
     };
   }
 
+  async function sessionList() {
+    const status = await computeStatus();
+    return {
+      activeSessionId: status.activeSessionId,
+      running: status.running,
+      sessions: status.sessions || []
+    };
+  }
+
+  async function sessionHistory(params) {
+    const sessionId = params && params.sessionId;
+    if (!sessionId) throw new Error('sessionId required');
+    if (api && api.sessions && typeof api.sessions.get === 'function') {
+      return api.sessions.get({ sessionId });
+    }
+    const status = await computeStatus();
+    const s = (status.sessions || []).find((x) => x.sessionId === sessionId);
+    if (!s) throw new Error('session not found: ' + sessionId);
+    return s;
+  }
+
   async function invoke(method, params) {
     params = params || {};
     if (method === 'harness.status') return computeStatus();
     if (method === 'harness.prompt') return harnessPrompt(params);
     if (method === 'harness.cancel') return harnessCancel();
     if (method === 'harness.balance') return harnessBalance();
+    if (method === 'session.list') return sessionList();
+    if (method === 'session.history') return sessionHistory(params);
     const dot = method.indexOf('.');
     if (dot <= 0) throw new Error('unknown method ' + method);
     const domain = method.slice(0, dot);