Sync workflow definition types from Core

Why: The frontend contract mirror has to include script steps and critic fields before a workflow can be described to the client.
Evidence: make contracts copied modules/core/ts/types.ts. No screen or event changed.
Impact: contracts.ts only. The existing plan, inbox, and HITL cards stay the UI.
Refs: feature/agent-harness-p4
Co-authored-by: Cursor <cursoragent@cursor.com>

src/contracts.ts

@@ -262,6 +262,36 @@ export interface PluginPanel {
   id: string; title: string; icon?: string; body: UINode[]; refreshTool?: string;
 }
 
+/** 模板占位符：{{input}}、{{slots.<key>}}、{{steps.<id>.output}}。 */
+export interface WorkflowDef {
+  id: string; title: string; description?: string; intentId?: string;
+  /** 整条工作流的 critic 重试上限。 */
+  maxRetries?: number;
+  steps: WorkflowStep[];
+}
+
+export interface StepCritic {
+  criteria: string;
+  /** 本步重试上限；缺省 1 次。 */
+  maxRetries?: number;
+}
+
+export interface WorkflowStep {
+  id: string; title: string;
+  kind: 'prompt' | 'tool' | 'hitl' | 'artifact' | 'card' | 'script';
+  prompt?: string;
+  /** prompt 步骤的子代理 profile，缺省 general。 */
+  agent?: string;
+  tool?: string;
+  args?: unknown;
+  hitl?: { question: string; kind: HITLKind; choices?: HITLChoice[]; allowFreeInput: boolean; freeInputHint?: string };
+  artifact?: string;
+  card?: { kind: CardKind; title: string; tone?: string; body?: UINode[]; actions?: { id: string; label: string; style?: 'primary' | 'default' | 'danger'; command?: string }[] };
+  /** script 步骤在插件目录内的相对路径。 */
+  script?: string;
+  critic?: StepCritic;
+}
+
 export interface PluginWorkspace {
   id: string; title: string; icon?: string; shortcut?: string;
   badgeTool?: string; body: UINode[]; refreshTool?: string;