新增: 工作流条件表达式 UI 补齐 i18n 翻译

条件表达式引擎早在 df-workflow/conditions.rs 完成,执行器(executor.rs)
按入边 condition 过滤也已落地,WorkflowDagDisplay.vue 提供边条件编辑
入口。但前端用 || '中文兜底' 说明 i18n 缺失,本次补齐中英文翻译:

zh-CN/taskDetail.ts + en/taskDetail.ts 同步新增:
- workflowDagTitle / workflowLayer / workflowDagEmpty
- workflowEdgeDetail / workflowUnconditional / workflowCondPlaceholder

核验确认条件引擎全部链路(引擎/feature flag/执行器集成/UI/i18n)
均已落地,F-09 B 路线(多会话并发)亦已完成批2/批4/批5 per_conv
隔离改造。

src/i18n/en/taskDetail.ts

@@ -55,5 +55,12 @@ export default {
     workflowStepsProgress: '{done} / {total} steps done',
     workflowCompletedHint: 'Workflow completed, task advanced',
     workflowFailedHint: 'Workflow failed, task rolled back',
+    // Workflow DAG display (WorkflowDagDisplay.vue)
+    workflowDagTitle: 'Workflow Structure',
+    workflowLayer: 'Layer',
+    workflowDagEmpty: 'No workflow data',
+    workflowEdgeDetail: 'Edge Condition Editor',
+    workflowUnconditional: 'Unconditional',
+    workflowCondPlaceholder: 'Enter condition expression (e.g. outputs.done == true)',
   },
 }