Improve workflow error messaging

lib/server/tasks.ts

@@ -3,6 +3,7 @@ import { getRun, start } from 'workflow/api';
 import type { WorkflowRunStatus } from '@workflow/world';
 import type { Task, TaskStatus, TaskTimeline, TaskType } from '@/lib/types';
 import { runTaskWorkflow } from '@/app/workflows/task-runner';
+import { describeTaskFailure } from '@/lib/server/task-errors';
 import {
   countTasksByStatus,
   createTaskRunRecord,
@@ -65,21 +66,24 @@ async function reconcileTaskWithWorkflow(task: Task) {
       return task;
     }
 
-    const nextError = nextStatus === 'failed'
-      ? workflowStatus === 'cancelled'
-        ? 'Workflow run cancelled'
-        : 'Workflow run failed'
+    const failure = nextStatus === 'failed'
+      ? describeTaskFailure(task, workflowStatus === 'cancelled' ? 'Workflow run cancelled' : 'Workflow run failed')
       : null;
 
-    const updated = await setTaskStatusFromWorkflow(task.id, nextStatus, nextError);
+    const updated = await setTaskStatusFromWorkflow(
+      task.id,
+      nextStatus,
+      failure?.detail ?? null,
+      failure?.summary ?? null
+    );
 
     const fallbackTask = {
       ...task,
       status: nextStatus,
       stage: nextStatus,
-      stage_detail: nextStatus === 'failed' ? nextError : 'Workflow run completed.',
+      stage_detail: nextStatus === 'failed' ? (failure?.summary ?? 'The background workflow stopped unexpectedly.') : 'Workflow run completed.',
       stage_context: null,
-      error: nextError,
+      error: failure?.detail ?? null,
       finished_at: nextStatus === 'queued' || nextStatus === 'running'
         ? null
         : task.finished_at ?? new Date().toISOString()
@@ -114,11 +118,14 @@ export async function enqueueTask(input: EnqueueTaskInput) {
       workflow_run_id: run.runId
     } satisfies Task;
   } catch (error) {
-    const reason = error instanceof Error
-      ? error.message
-      : 'Failed to start workflow';
-    await markTaskFailure(task.id, reason, 'failed');
-    throw error;
+    const failure = describeTaskFailure(task, 'Failed to start workflow');
+    await markTaskFailure(task.id, failure.detail, 'failed', {
+      detail: failure.summary
+    });
+
+    const wrapped = new Error(failure.detail);
+    (wrapped as Error & { cause?: unknown }).cause = error;
+    throw wrapped;
   }
 }