feat: add JavaScript session orchestration runtime

.ccweb/scripts/session-orchestration-e2e-20260826.js

@@ -0,0 +1,31 @@
+import {
+  createConversation,
+  sendMessage,
+  selectSemanticBranch,
+} from '@ccweb/session';
+
+const conversationId = await createConversation(
+  '这是 JavaScript 会话编排端到端测试。请只回复：测试成功'
+);
+
+const branch = await selectSemanticBranch(conversationId, [
+  '测试成功',
+  '测试失败',
+]);
+
+if (branch !== '测试成功') {
+  const error = new Error(`语义分支未命中测试成功：${branch}`);
+  error.code = 'unexpected_semantic_branch';
+  throw error;
+}
+
+const message = await sendMessage(
+  conversationId,
+  '收到。请只回复：已收到'
+);
+
+console.log(JSON.stringify({
+  conversationId,
+  branch,
+  message,
+}));