feat(workflow): add workflow engine, /workflows panel, /ultracode skill

将 feat/sdk-backend 分支中 workflow 相关的 20 个 commit 压缩为单 commit：

- 工作流引擎核心：phase / agent / parallel / pipeline 编排原语（packages/workflow-engine/）
- /workflows 面板：三区焦点布局（顶部 run tabs + 左侧 phase 侧栏 + 右侧 agent 列表）
- /ultracode skill：多 agent workflow 编排入口
- 进度存储 / journal / notification 系统
- WorkflowService 生命周期管理 + SentryErrorBoundary
- 脚本沙箱：禁用 dynamic import()、JSON args 防御性归一化
- journal 与 named-workflow 路径统一在 projectRoot
- 错误处理：parallel/pipeline hooks 错误日志、failure routing、semaphore abort
- workflow 工具升级为 core 工具 + PascalCase 命名

Co-Authored-By: glm-5.1 <zai-org@claude-code-best.win>

packages/workflow-engine/src/__tests__/context.test.ts

@@ -0,0 +1,76 @@
+import { expect, test } from 'bun:test'
+import { createBufferingEmitter } from '../progress/events.js'
+import {
+  createEngineContext,
+  createSharedResources,
+} from '../engine/context.js'
+import { WorkflowError } from '../engine/errors.js'
+import { createHostHandle, type WorkflowPorts } from '../ports.js'
+
+function mockPorts(): WorkflowPorts {
+  return {
+    agentRunner: { runAgentToResult: async () => ({ kind: 'dead' }) },
+    progressEmitter: { emit: () => {} },
+    taskRegistrar: {
+      register: () => ({ runId: 'r', signal: new AbortController().signal }),
+      complete: () => {},
+      fail: () => {},
+      kill: () => {},
+      pendingAction: () => null,
+    },
+    journalStore: {
+      read: async () => [],
+      append: async () => {},
+      truncate: async () => {},
+    },
+    permissionGate: { isAborted: () => false },
+    logger: { debug: () => {}, event: () => {} },
+    hostFactory: () => ({
+      handle: createHostHandle(null),
+      cwd: '/tmp',
+      budgetTotal: null,
+    }),
+  }
+}
+
+test('createSharedResources 初始化预算与计数', () => {
+  const r = createSharedResources(100)
+  expect(r.budget.total).toBe(100)
+  expect(r.agentCountBox.value).toBe(0)
+  expect(r.depth).toBe(0)
+})
+
+test('createEngineContext 复制 journal 并重置游标', () => {
+  const journal = [
+    {
+      key: 'k',
+      seq: 0,
+      result: { kind: 'ok' as const, output: 'x', usage: { outputTokens: 1 } },
+    },
+  ]
+  const ctx = createEngineContext({
+    ports: mockPorts(),
+    host: createHostHandle(null),
+    signal: new AbortController().signal,
+    runId: 'r1',
+    workflowName: 'w',
+    cwd: '/tmp',
+    budgetTotal: null,
+    journal,
+  })
+  expect(ctx.journal).toHaveLength(1)
+  expect(ctx.journalIndex).toBe(0)
+  expect(ctx.journalInvalidated).toBe(false)
+})
+
+test('createBufferingEmitter 收集事件', () => {
+  const { emitter, events } = createBufferingEmitter()
+  emitter.emit({ type: 'log', runId: 'r', message: 'hi' })
+  expect(events).toHaveLength(1)
+})
+
+test('WorkflowError 可识别', () => {
+  const e = new WorkflowError('boom')
+  expect(e).toBeInstanceOf(Error)
+  expect(e.message).toBe('boom')
+})