Handle card comment load rejection

frontend/taskdeck-web/src/composables/useCardModal.ts

@@ -138,7 +138,7 @@ export function useCardModal(options: UseCardModalOptions) {
           boardStore.setEditingCard(null)
         }
         boardStore.setEditingCard(newCard.id)
-        void boardStore.fetchCardComments(newCard.boardId, newCard.id)
+        void loadCardComments(newCard)
         void loadCaptureProvenance()
       }
     }
@@ -149,7 +149,7 @@ export function useCardModal(options: UseCardModalOptions) {
     async (isOpen) => {
       if (isOpen) {
         expectedUpdatedAt.value = card.value.updatedAt
-        await boardStore.fetchCardComments(card.value.boardId, card.value.id)
+        void loadCardComments(card.value)
         await loadCaptureProvenance()
         boardStore.setEditingCard(card.value.id)
         return
@@ -176,6 +176,15 @@ export function useCardModal(options: UseCardModalOptions) {
     { immediate: true }
   )
 
+  function loadCardComments(targetCard: Card) {
+    return boardStore.fetchCardComments(targetCard.boardId, targetCard.id).catch((error: unknown) => {
+      // The store owns the user-facing error state and toast. Keep cached comments intact
+      // and let the rest of the card editor continue loading, but never swallow the failure
+      // silently: this is the only reporting sink once the rejection is caught here.
+      logError('Failed to load card comments:', error)
+    })
+  }
+
   // Provenance
   async function loadCaptureProvenance() {
     const targetCard = card.value

frontend/taskdeck-web/src/tests/components/CardModal.spec.ts

@@ -103,6 +103,65 @@ describe('CardModal', () => {
     expect(mockStore.fetchCardProvenance).toHaveBeenCalledTimes(1)
   })
 
+  it('keeps the editor and cached comments usable when comment loading fails', async () => {
+    mockStore.getCardComments.mockReturnValue([makeOwnComment()])
+    mockStore.fetchCardComments.mockRejectedValue(new Error('comments unavailable'))
+
+    const wrapper = mount(CardModal, {
+      props: { card, isOpen: true, labels },
+    })
+    await flushPromises()
+
+    expect(wrapper.get('#card-title').exists()).toBe(true)
+    expect(wrapper.text()).toContain('Delete me')
+    expect(mockStore.fetchCardProvenance).toHaveBeenCalledWith('board-1', 'card-1')
+    expect(mockStore.setEditingCard).toHaveBeenCalledWith('card-1')
+
+    wrapper.unmount()
+  })
+
+  it('does not let a stale comment rejection disturb a newer card session', async () => {
+    const firstLoad = createDeferred<CardComment[]>()
+    const secondLoad = createDeferred<CardComment[]>()
+    const firstComment = makeOwnComment()
+    const secondComment: CardComment = {
+      ...firstComment,
+      id: 'comment-2',
+      cardId: 'card-2',
+      content: 'Card B comment',
+    }
+    mockStore.fetchCardComments.mockImplementation((_boardId: string, cardId: string) => (
+      cardId === 'card-1' ? firstLoad.promise : secondLoad.promise
+    ))
+    mockStore.getCardComments.mockImplementation((cardId: string) => (
+      cardId === 'card-1' ? [firstComment] : [secondComment]
+    ))
+
+    const wrapper = mount(CardModal, {
+      props: { card, isOpen: true, labels },
+    })
+    await nextTick()
+
+    const secondCard: Card = {
+      ...card,
+      id: 'card-2',
+      title: 'Card B',
+      updatedAt: '2026-08-26T12:00:00.000Z',
+    }
+    await wrapper.setProps({ card: secondCard })
+    await nextTick()
+
+    firstLoad.reject(new Error('stale comments unavailable'))
+    secondLoad.resolve([secondComment])
+    await flushPromises()
+
+    expect((wrapper.get('#card-title').element as HTMLInputElement).value).toBe('Card B')
+    expect(wrapper.text()).toContain('Card B comment')
+    expect(mockStore.setEditingCard).toHaveBeenLastCalledWith('card-2')
+
+    wrapper.unmount()
+  })
+
   it('keeps provenance responses scoped to the card that requested them', async () => {
     let resolveFirst!: (value: any) => void
     let resolveSecond!: (value: any) => void