Keep the knowledge graph when one schedule fails to load

One failing per-schedule request no longer blanks the whole graph, and
the graph shows the engine's own error instead of always saying the
engine cannot be reached.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/express/results.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { correctIndex, questionsOf, toMarkdown, withPlanItem, type Material } from './results'
+import { correctIndex, keepSettled, questionsOf, toMarkdown, withPlanItem, type Material } from './results'
 import { sentencesOf, scriptLang } from '../components/AudioPlayer'
 
 describe('correctIndex', () => {
@@ -65,3 +65,20 @@ describe('withPlanItem', () => {
     expect(withPlanItem('preparing', undefined)).toBe('preparing')
   })
 })
+
+describe('keepSettled', () => {
+  const ok = (v: number[]): PromiseSettledResult<number[]> => ({ status: 'fulfilled', value: v })
+  const bad = (message: string): PromiseSettledResult<number[]> => ({ status: 'rejected', reason: new Error(message) })
+
+  it('leaves out a schedule that failed', () => {
+    expect(keepSettled([ok([1, 2]), bad('404'), ok([3])])).toEqual([1, 2, 3])
+  })
+
+  it('fails when every schedule failed', () => {
+    expect(() => keepSettled([bad('500'), bad('502')])).toThrow('500')
+  })
+
+  it('is empty without schedules', () => {
+    expect(keepSettled([])).toEqual([])
+  })
+})

src/express/results.ts

@@ -172,14 +172,24 @@ async function sourcesOf({ agent, rule }: Schedule): Promise<FoundSource[]> {
   }))
 }
 
+// One schedule the engine cannot answer for (e.g. an archived agent) leaves its results out
+// instead of failing them all; only when every schedule fails is that an error.
+export function keepSettled<T>(results: PromiseSettledResult<T[]>[]): T[] {
+  const kept = results.flatMap(r => (r.status === 'fulfilled' ? r.value : []))
+  const failed = results.filter(r => r.status === 'rejected')
+  if (failed.length) console.warn(`${failed.length} of ${results.length} schedules could not be loaded`, failed.map(r => r.reason))
+  if (results.length && failed.length === results.length) throw failed[0].reason
+  return kept
+}
+
 export async function listResults(): Promise<{ materials: Material[]; sources: FoundSource[] }> {
   const schedules = await expressAgents({ archived: true })
   const [materials, sources] = await Promise.all([
-    Promise.all(schedules.filter(s => s.rule.type === 'content').map(materialsOf)),
+    Promise.allSettled(schedules.filter(s => s.rule.type === 'content').map(materialsOf)),
-    Promise.all(schedules.filter(s => s.rule.type === 'research').map(sourcesOf)),
+    Promise.allSettled(schedules.filter(s => s.rule.type === 'research').map(sourcesOf)),
   ])
   const newest = <T extends { createdAt: string }>(a: T, b: T) => b.createdAt.localeCompare(a.createdAt)
-  return { materials: materials.flat().sort(newest), sources: sources.flat().sort(newest) }
+  return { materials: keepSettled(materials).sort(newest), sources: keepSettled(sources).sort(newest) }
 }
 
 const draftContent = (m: Material, id: number) =>

src/pages/Production.tsx

@@ -92,7 +92,8 @@ export function ProductionPage() {
         </button>
         {graph
           ? <KnowledgeGraph graph={graph} />
-          : <div className="graph-loading" role="status">{docs.isError || results.isError ? t('brain.engineDown') : t('prod.loadingGraph')}</div>}
+          // The engine's own message: an unreachable engine says so, any other failure says what it was.
+          : <div className="graph-loading" role="status">{(docs.error ?? results.error)?.message ?? t('prod.loadingGraph')}</div>}
 
         <aside className="graph-panel">
           <div className="graph-stats">