feat(PBI-91): expliciete schermstaat + draft-zichtbaarheid PB-page (#210)

* docs(ST-1369): plan PBI-91 — expliciete schermstaat + draft-zichtbaarheid Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(ST-1369): screen-state module — ScreenState + deriveScreenState() Pure afleidingslaag die de verspreide schermstaat-derivatie van de Product Backlog page consolideert tot één testbaar ScreenState-model. Nog geen consumers — die volgen in T-1035/T-1036. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * test(ST-1369): unit-tests voor deriveScreenState() Dekt alle vier de kinds (NO_SPRINT, DRAFT, ACTIVE, EDITING), de building-flag en de draft-voorrang boven een actieve sprint. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(ST-1369): SprintSwitcher op deriveScreenState + draft op trigger (G5) De trigger-knop toont nu de concept-sprint zodra er een sprint-draft loopt, niet langer alleen de (disabled) dropdown-regel. Schermstaat-afleiding loopt via de pure deriveScreenState() i.p.v. losse flags. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * feat(ST-1369): NewSprintTrigger achter isActiveProduct-gate (G6) De "Nieuwe sprint"-knop rendert niet langer op een niet-actief product — een sprint-draft starten daar was verwarrend. page.tsx geeft de bestaande isActiveProduct-flag door. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * test(ST-1369): component-tests voor draft-op-trigger (G5) en isActiveProduct-gate (G6) sprint-switcher: trigger toont concept-sprint bij een pending draft, en geen concept-label zonder draft. new-sprint-trigger: nieuw testbestand — rendert niet op een niet-actief product, wel op een actief product zonder draft. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-15 01:45:35 +02:00 · 2026-05-15 01:45:35 +02:00 · 3d5c22382c
commit 3d5c22382c
parent 2a6386163c
9 changed files with 351 additions and 8 deletions
--- a/tests/components/backlog/new-sprint-trigger.test.tsx
+++ b/tests/components/backlog/new-sprint-trigger.test.tsx
@ -0,0 +1,57 @@
+// @vitest-environment jsdom
+import { describe, it, expect, beforeEach, vi } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import '@testing-library/jest-dom'
+import type { ReactNode } from 'react'
+
+const workflowMock: {
+  value: { pendingSprintDraft?: Record<string, unknown> } | undefined
+} = { value: undefined }
+
+vi.mock('@/stores/user-settings/store', () => ({
+  useUserSettingsStore: (
+    selector: (s: {
+      entities: {
+        settings: {
+          workflow: { pendingSprintDraft?: Record<string, unknown> } | undefined
+        }
+      }
+    }) => unknown,
+  ) => selector({ entities: { settings: { workflow: workflowMock.value } } }),
+}))
+
+vi.mock('./new-sprint-metadata-dialog', () => ({
+  NewSprintMetadataDialog: () => null,
+}))
+
+vi.mock('@/components/shared/demo-tooltip', () => ({
+  DemoTooltip: ({ children }: { children: ReactNode }) => children,
+}))
+
+import { NewSprintTrigger } from '@/components/backlog/new-sprint-trigger'
+
+beforeEach(() => {
+  workflowMock.value = undefined
+})
+
+describe('NewSprintTrigger', () => {
+  it('renders the button on an active product without a draft', () => {
+    render(<NewSprintTrigger productId="p1" isDemo={false} isActiveProduct={true} />)
+    expect(screen.getByText('Nieuwe sprint')).toBeInTheDocument()
+  })
+
+  it('renders nothing on a non-active product (G6)', () => {
+    const { container } = render(
+      <NewSprintTrigger productId="p1" isDemo={false} isActiveProduct={false} />,
+    )
+    expect(container).toBeEmptyDOMElement()
+  })
+
+  it('renders nothing when a sprint draft is pending', () => {
+    workflowMock.value = { pendingSprintDraft: { p1: { goal: 'X' } } }
+    const { container } = render(
+      <NewSprintTrigger productId="p1" isDemo={false} isActiveProduct={true} />,
+    )
+    expect(container).toBeEmptyDOMElement()
+  })
+})
--- a/tests/components/shared/sprint-switcher.test.tsx
+++ b/tests/components/shared/sprint-switcher.test.tsx
@ -24,6 +24,11 @@ vi.mock('sonner', () => ({
 }))

 const isDemoMock = { value: false }
+const workflowMock: {
+  value:
+    | { pendingSprintDraft?: Record<string, { goal: string } | undefined> }
+    | undefined
+} = { value: undefined }
 // Mock-state shape moet alle paden dekken die SprintSwitcher selecteert:
 // - s.context.isDemo (oude code)
 // - s.entities.settings.workflow?.pendingSprintDraft?.[productId]?.goal (PBI-79)
@ -38,8 +43,11 @@ type MockStoreState = {
  }
 }
 vi.mock('@/stores/user-settings/store', () => ({
-  useUserSettingsStore: (selector: (s: { context: { isDemo: boolean }; entities: { settings: { workflow: null } } }) => unknown) =>
-    selector({ context: { isDemo: isDemoMock.value }, entities: { settings: { workflow: null } } }),
+  useUserSettingsStore: (selector: (s: MockStoreState) => unknown) =>
+    selector({
+      context: { isDemo: isDemoMock.value },
+      entities: { settings: { workflow: workflowMock.value } },
+    }),
 }))

 vi.mock('@/components/ui/dropdown-menu', () => {
@ -85,6 +93,7 @@ const sprints = [
 beforeEach(() => {
  vi.clearAllMocks()
  isDemoMock.value = false
+  workflowMock.value = undefined
  actionMock.mockResolvedValue({ success: true })
  pathnameMock.mockReturnValue('/products/p1/sprint')
 })
@ -137,4 +146,29 @@ describe('SprintSwitcher', () => {
    expect(pushMock).not.toHaveBeenCalled()
    expect(actionMock).not.toHaveBeenCalled()
  })
+
+  it('shows the concept-sprint on the trigger when a draft is pending (G5)', () => {
+    workflowMock.value = { pendingSprintDraft: { p1: { goal: 'Test goal' } } }
+    render(
+      <SprintSwitcher
+        productId="p1"
+        sprints={sprints}
+        activeSprint={null}
+        buildingSprintIds={[]}
+      />,
+    )
+    expect(screen.getByText('⚙ Concept — Test goal')).toBeInTheDocument()
+  })
+
+  it('shows no concept label on the trigger when no draft is pending', () => {
+    render(
+      <SprintSwitcher
+        productId="p1"
+        sprints={sprints}
+        activeSprint={sprints[0]}
+        buildingSprintIds={[]}
+      />,
+    )
+    expect(screen.queryByText(/⚙ Concept/)).not.toBeInTheDocument()
+  })
 })
--- a/tests/stores/product-workspace/screen-state.test.ts
+++ b/tests/stores/product-workspace/screen-state.test.ts
@ -0,0 +1,83 @@
+import { describe, it, expect } from 'vitest'
+import {
+  deriveScreenState,
+  type ScreenStateInput,
+} from '@/stores/product-workspace/screen-state'
+
+const base: ScreenStateInput = {
+  activeSprintItem: null,
+  buildingSprintIds: [],
+  hasPendingDraft: false,
+  pendingAdds: [],
+  pendingRemoves: [],
+}
+
+describe('deriveScreenState', () => {
+  it('returns NO_SPRINT without draft or active sprint', () => {
+    expect(deriveScreenState(base)).toEqual({ kind: 'NO_SPRINT' })
+  })
+
+  it('returns DRAFT when a pending draft exists', () => {
+    expect(deriveScreenState({ ...base, hasPendingDraft: true })).toEqual({
+      kind: 'DRAFT',
+    })
+  })
+
+  it('lets a draft win over an active sprint with pending changes', () => {
+    expect(
+      deriveScreenState({
+        ...base,
+        hasPendingDraft: true,
+        activeSprintItem: { id: 's1' },
+        pendingAdds: ['x'],
+      }),
+    ).toEqual({ kind: 'DRAFT' })
+  })
+
+  it('returns ACTIVE for an active sprint with no pending changes', () => {
+    expect(
+      deriveScreenState({ ...base, activeSprintItem: { id: 's1' } }),
+    ).toEqual({ kind: 'ACTIVE', building: false })
+  })
+
+  it('flags building when the active sprint is in buildingSprintIds', () => {
+    expect(
+      deriveScreenState({
+        ...base,
+        activeSprintItem: { id: 's1' },
+        buildingSprintIds: ['s1'],
+      }),
+    ).toEqual({ kind: 'ACTIVE', building: true })
+  })
+
+  it('returns EDITING when there are pending adds', () => {
+    expect(
+      deriveScreenState({
+        ...base,
+        activeSprintItem: { id: 's1' },
+        pendingAdds: ['x'],
+      }),
+    ).toEqual({ kind: 'EDITING', building: false })
+  })
+
+  it('returns EDITING when there are pending removes', () => {
+    expect(
+      deriveScreenState({
+        ...base,
+        activeSprintItem: { id: 's1' },
+        pendingRemoves: ['y'],
+      }),
+    ).toEqual({ kind: 'EDITING', building: false })
+  })
+
+  it('flags building on EDITING when the active sprint is building', () => {
+    expect(
+      deriveScreenState({
+        ...base,
+        activeSprintItem: { id: 's1' },
+        pendingAdds: ['x'],
+        buildingSprintIds: ['s1'],
+      }),
+    ).toEqual({ kind: 'EDITING', building: true })
+  })
+})
--- a/app/(app)/products/[id]/page.tsx
+++ b/app/(app)/products/[id]/page.tsx
@ -131,7 +131,13 @@ export default async function ProductBacklogPage({ params, searchParams }: Props
          {activeSprintItem && !isDemo && (
            <SaveSprintButton activeSprintId={activeSprintItem.id} />
          )}
-          {!isDemo && <NewSprintTrigger productId={id} isDemo={isDemo} />}
+          {!isDemo && (
+            <NewSprintTrigger
+              productId={id}
+              isDemo={isDemo}
+              isActiveProduct={isActiveProduct}
+            />
+          )}
          {!isDemo && product.user_id === session.userId && (
            <EditProductButton
              product={{
--- a/components/backlog/new-sprint-trigger.tsx
+++ b/components/backlog/new-sprint-trigger.tsx
@ -9,20 +9,27 @@ import { NewSprintMetadataDialog } from './new-sprint-metadata-dialog'
 interface NewSprintTriggerProps {
  productId: string
  isDemo: boolean
+  isActiveProduct: boolean
 }

 /**
 * PBI-79 / ST-1337: trigger-knop voor de nieuwe sprint-flow.
 * Verbergt zichzelf wanneer er al een pendingSprintDraft loopt — dan
- * staat de SprintDefinitionBanner zelf de afronding te regelen.
+ * staat de SprintDefinitionBanner zelf de afronding te regelen — en
+ * wanneer het product niet het actieve product is (ST-1369 / G6).
 */
-export function NewSprintTrigger({ productId, isDemo }: NewSprintTriggerProps) {
+export function NewSprintTrigger({
+  productId,
+  isDemo,
+  isActiveProduct,
+}: NewSprintTriggerProps) {
  const [open, setOpen] = useState(false)
  const hasDraft = useUserSettingsStore(
    (s) => !!s.entities.settings.workflow?.pendingSprintDraft?.[productId],
  )

  if (hasDraft) return null
+  if (!isActiveProduct) return null

  return (
    <>
--- a/components/shared/sprint-switcher.tsx
+++ b/components/shared/sprint-switcher.tsx
@ -18,6 +18,7 @@ import {
  switchActiveSprintAction,
 } from '@/actions/active-sprint'
 import { useProductWorkspaceStore } from '@/stores/product-workspace/store'
+import { deriveScreenState } from '@/stores/product-workspace/screen-state'
 import { useUserSettingsStore } from '@/stores/user-settings/store'
 import type { SprintStatusApi } from '@/lib/task-status'
 import { debugProps } from '@/lib/debug'
@ -57,6 +58,20 @@ export function SprintSwitcher({
  const draftGoal = useUserSettingsStore(
    (s) => s.entities.settings.workflow?.pendingSprintDraft?.[productId]?.goal ?? null,
  )
+  const pendingAdds = useProductWorkspaceStore(
+    (s) => s.sprintMembership.pending.adds,
+  )
+  const pendingRemoves = useProductWorkspaceStore(
+    (s) => s.sprintMembership.pending.removes,
+  )
+
+  const screenState = deriveScreenState({
+    activeSprintItem: activeSprint,
+    buildingSprintIds,
+    hasPendingDraft: draftGoal !== null,
+    pendingAdds,
+    pendingRemoves,
+  })

  const visibleSprints = sprints.filter(s => {
    if (showClosed) return true
@ -139,10 +154,19 @@ export function SprintSwitcher({
        disabled={isPending}
        className="flex items-center gap-1.5 text-sm text-muted-foreground hover:text-foreground transition-colors px-2 py-1 rounded-md hover:bg-surface-container focus:outline-none"
      >
-        <span className="truncate max-w-[160px]">
-          {activeSprint ? activeSprint.code : 'Selecteer sprint'}
+        <span
+          className={cn(
+            'truncate max-w-[160px]',
+            screenState.kind === 'DRAFT' && 'italic text-tertiary',
+          )}
+        >
+          {screenState.kind === 'DRAFT'
+            ? `⚙ Concept — ${draftGoal}`
+            : activeSprint
+              ? activeSprint.code
+              : 'Selecteer sprint'}
        </span>
-        {activeSprint && (
+        {screenState.kind !== 'DRAFT' && activeSprint && (
          <span
            className={cn(
              'text-sm',
--- a/docs/INDEX.md
+++ b/docs/INDEX.md
@ -48,6 +48,7 @@ Auto-generated on 2026-05-14 from front-matter and headings.
 | [Plan v3.5 — Bootstrap-wizard voor nieuwe Product-repo (Scrum4Me feature)](./plans/M8-bootstrap-wizard.md) | reviewed | — |
 | [PBI-80 — Demo-gebruiker mag eigen UI-voorkeuren wijzigen](./plans/PBI-80-demo-prefs.md) | — | — |
 | [Plan — `code` wordt bindende volgorde voor stories & taken; drag-and-drop eruit](./plans/PBI-84-code-binding-order.md) | — | — |
+| [Plan — Expliciete schermstaat + draft-zichtbaarheid op de Product Backlog page](./plans/PBI-91-pb-screen-state.md) | — | — |
 | [Queue-loop verplaatsen van Claude naar runner](./plans/queue-loop-extraction.md) | — | — |
 | [Sprint MCP-tools — create_sprint & update_sprint](./plans/sprint-mcp-tools.md) | draft | 2026-05-11 |
 | [Advies - SprintRun, PR en worktree lifecycle als state machines](./plans/sprint-pr-worktree-state-machines.md) | draft | 2026-05-06 |
--- a/docs/plans/PBI-91-pb-screen-state.md
+++ b/docs/plans/PBI-91-pb-screen-state.md
@ -0,0 +1,98 @@
+# Plan — Expliciete schermstaat + draft-zichtbaarheid op de Product Backlog page
+
+> **Status:** goedgekeurd 2026-05-15 · gematerialiseerd via Scrum4Me-MCP.
+> **PBI-91** · Story **ST-1369** (OPEN — in de productbacklog, geen sprint) · Taken **T-1033 t/m T-1037** (uitvoervolgorde = sort_order 1–5).
+>
+> Vervolg op **PBI-88** ("Product Backlog page workflow & states", PR #208) — implementeert 3 van de 4 niet-bindende aanbevelingen uit `docs/architecture/product-backlog-workflow.md`. G3 uitgesteld.
+
+## Context
+
+PBI-88 leverde een as-is/to-be analyse op: [docs/architecture/product-backlog-workflow.md](../architecture/product-backlog-workflow.md). Dat doc sluit af met vier **niet-bindende** aanbevelingen (G1, G3, G5, G6) als "input voor latere PBI's".
+
+Deze PBI implementeert er **drie** van. **G3** (expliciete ERROR-schermstaat) wordt **uitgesteld** — het doc zegt zelf "alleen oppakken als falende commits of SSE-verlies een echt UX-probleem blijken", en het is meer een ontwerpkeuze dan een heldere implementatie.
+
+De directe aanleiding voor PBI-88 was een **bug**: de concept-sprint (`pendingSprintDraft`) is niet zichtbaar op de SprintSwitcher-trigger-knop — alleen in de (disabled) dropdown. Dat is **G5** en wordt hier opgelost.
+
+**Scope:**
+- **G1** — `deriveScreenState()`: één pure functie die de vandaag verspreide schermstaat-afleiding consolideert.
+- **G5** — draft-status zichtbaar op de SprintSwitcher-trigger (de oorspronkelijke bug).
+- **G6** — `NewSprintTrigger` achter een `isActiveProduct`-gate.
+- **G3** — *uitgesteld*, vastgelegd als follow-up.
+
+## Aanpak
+
+### Nieuwe bestanden
+
+**`stores/product-workspace/screen-state.ts`** — pure module, géén React, spiegelt `selectors.ts`:
+
+```ts
+export type ScreenState =
+  | { kind: 'NO_SPRINT' }
+  | { kind: 'DRAFT' }
+  | { kind: 'ACTIVE'; building: boolean }
+  | { kind: 'EDITING'; building: boolean }
+
+export interface ScreenStateInput {
+  activeSprintItem: { id: string } | null   // SSR-prop uit page.tsx
+  buildingSprintIds: string[]               // SSR-prop uit page.tsx
+  hasPendingDraft: boolean                  // user-settings store
+  pendingAdds: string[]                     // product-workspace store
+  pendingRemoves: string[]                  // product-workspace store
+}
+
+export function deriveScreenState(i: ScreenStateInput): ScreenState {
+  if (i.hasPendingDraft) return { kind: 'DRAFT' }            // draft wint van alles
+  if (i.activeSprintItem) {
+    const building = i.buildingSprintIds.includes(i.activeSprintItem.id)
+    const dirty = i.pendingAdds.length > 0 || i.pendingRemoves.length > 0
+    return dirty ? { kind: 'EDITING', building } : { kind: 'ACTIVE', building }
+  }
+  return { kind: 'NO_SPRINT' }
+}
+```
+
+Bewust **geen** `useScreenState`-hook: consumers roepen `deriveScreenState()` inline aan met store-slices + SSR-props. `ScreenStateInput` is daar precies voor ontworpen. Hook-extractie is "straks" als meer componenten meedoen — niet nu. `PRODUCT_NOT_ACTIVE` en `DEMO_MODE` blijven **buiten** `ScreenState` (gates, geen knopen — conform het doc).
+
+**`__tests__/stores/product-workspace/screen-state.test.ts`** — pure input→output tests, patroon van [__tests__/lib/product-switch-path.test.ts](../../__tests__/lib/product-switch-path.test.ts) (vitest, geen mocks).
+
+### Te wijzigen bestanden
+
+| Bestand | Wijziging |
+|---|---|
+| [components/shared/sprint-switcher.tsx](../../components/shared/sprint-switcher.tsx) | Leest `pendingAdds`/`pendingRemoves` uit `useProductWorkspaceStore`; `hasPendingDraft` = bestaand `draftGoal !== null` (regel 57). Roept `deriveScreenState()` aan. Trigger-label (regel 142-156) vertakt op `screenState.kind`: bij `DRAFT` toont de **trigger** `⚙ Concept — {draftGoal}` i.p.v. "Selecteer sprint"; status/BUILDING-badge verborgen in `DRAFT`. **(G1 + G5)** |
+| [components/backlog/new-sprint-trigger.tsx](../../components/backlog/new-sprint-trigger.tsx) | `isActiveProduct: boolean` toevoegen aan props; `if (!isActiveProduct) return null` — spiegelt het bestaande `if (hasDraft) return null` patroon (regel 25). **(G6)** |
+| [app/(app)/products/[id]/page.tsx](../../app/(app)/products/%5Bid%5D/page.tsx) | Regel 134: `isActiveProduct={isActiveProduct}` doorgeven aan `NewSprintTrigger` (`isActiveProduct` bestaat al op regel 49). **(G6)** |
+| [__tests__/components/shared/sprint-switcher.test.tsx](../../__tests__/components/shared/sprint-switcher.test.tsx) | Uitbreiden: trigger toont "⚙ Concept" als er een draft is. **(G5)** |
+| `__tests__/components/backlog/new-sprint-trigger.test.tsx` | Toevoegen of uitbreiden: component returnt `null` bij `isActiveProduct={false}`. **(G6)** |
+
+### Hergebruik (niets nieuws bouwen)
+
+- Pure-selector-patroon: `selectIsDirty` / `selectPendingCount` — [stores/product-workspace/selectors.ts:166](../../stores/product-workspace/selectors.ts:166)
+- Bestaande `draftGoal`-selector — [components/shared/sprint-switcher.tsx:57](../../components/shared/sprint-switcher.tsx:57)
+- Bestaande `buildingSet`-logica voor dropdown-items — [components/shared/sprint-switcher.tsx:51](../../components/shared/sprint-switcher.tsx:51)
+- `sprintMembership.pending` shape `{ adds, removes }` — bestaande store-slice
+- Test-patroon pure functie — [__tests__/lib/product-switch-path.test.ts](../../__tests__/lib/product-switch-path.test.ts)
+
+## Taken (Story ST-1369)
+
+| Code | Taak | Kern |
+|---|---|---|
+| T-1033 | `screen-state.ts` — `ScreenState` type + pure `deriveScreenState()` | Nieuw bestand, pure module |
+| T-1034 | Unit tests `screen-state.test.ts` | 4 kinds + `building`-flag + precedence (draft wint) |
+| T-1035 | `SprintSwitcher` op `deriveScreenState()` + G5: draft op de trigger-knop | G1-wiring + G5 |
+| T-1036 | `NewSprintTrigger` achter `isActiveProduct`-gate (component + `page.tsx`) | G6 |
+| T-1037 | Component-tests: sprint-switcher (G5) + new-sprint-trigger (G6) | Regressie-dekking |
+
+## Verificatie
+
+- `npm run verify` — lint + typecheck + test (de lokale gate; `npm run build` kan in een worktree falen op ontbrekende `DATABASE_URL`)
+- `npm test -- screen-state` — de nieuwe pure-functie-tests geïsoleerd
+- `npm run dev` + browser:
+  - **G5**: start een nieuwe sprint-draft → de SprintSwitcher-**trigger** toont "⚙ Concept — [goal]" (niet alleen de dropdown)
+  - **G5**: annuleer de draft → trigger valt terug op sprint-code / "Selecteer sprint"
+  - **G6**: open een **niet-actief** product → de "Nieuwe sprint"-knop is afwezig; activeer het product → knop verschijnt
+  - regressie: actieve sprint zonder draft toont gewoon code + status/BUILDING-badge
+
+## Uitgesteld (follow-up)
+
+**G3 — expliciete ERROR-schermstaat.** Vandaag: server-action-fout → `toast.error`, scherm blijft in huidige state. Reden uitstel: het doc adviseert dit alleen op te pakken als falende commits of SSE-verlies een aantoonbaar UX-probleem blijken; ERROR past bovendien niet natuurlijk in de pure `deriveScreenState()` (een fout is geen afgeleide van de input-flags). Vereist eerst een aparte ontwerpkeuze.
--- a/stores/product-workspace/screen-state.ts
+++ b/stores/product-workspace/screen-state.ts
@ -0,0 +1,33 @@
+// Expliciete schermstaat voor de Product Backlog page.
+//
+// Consolideert de vandaag verspreide schermstaat-afleiding (page.tsx,
+// sprint-switcher.tsx, new-sprint-trigger.tsx, save-sprint-button.tsx) tot één
+// pure, testbare functie. Zie docs/architecture/product-backlog-workflow.md,
+// sectie "To-be: expliciete state machine".
+//
+// PRODUCT_NOT_ACTIVE en DEMO_MODE blijven bewust BUITEN ScreenState — het zijn
+// cross-cutting gates, geen knopen in de state machine.
+
+export type ScreenState =
+  | { kind: 'NO_SPRINT' }
+  | { kind: 'DRAFT' }
+  | { kind: 'ACTIVE'; building: boolean }
+  | { kind: 'EDITING'; building: boolean }
+
+export interface ScreenStateInput {
+  activeSprintItem: { id: string } | null // SSR-prop uit page.tsx
+  buildingSprintIds: string[] // SSR-prop uit page.tsx
+  hasPendingDraft: boolean // user-settings store
+  pendingAdds: string[] // product-workspace store: sprintMembership.pending.adds
+  pendingRemoves: string[] // product-workspace store: sprintMembership.pending.removes
+}
+
+export function deriveScreenState(i: ScreenStateInput): ScreenState {
+  if (i.hasPendingDraft) return { kind: 'DRAFT' } // draft wint van alles
+  if (i.activeSprintItem) {
+    const building = i.buildingSprintIds.includes(i.activeSprintItem.id)
+    const dirty = i.pendingAdds.length > 0 || i.pendingRemoves.length > 0
+    return dirty ? { kind: 'EDITING', building } : { kind: 'ACTIVE', building }
+  }
+  return { kind: 'NO_SPRINT' }
+}