actions: promoteTodoToIdeaAction (M12 T-499)

actions/todos.ts:
- promoteTodoToIdeaAction(todoId): auth + demo + scope + already-archived
  guards. Atomic \$transaction creates DRAFT Idea (with auto IDEA-NNN code)
  and archives source Todo + IdeaLog{NOTE}.
- Anders dan Todo→PBI/Story (die de todo deleten): we ARCHIVEREN. De idea
  wordt het nieuwe planningsartifact; de archived todo bewaart het
  vertrekpunt (zie M12 grill-keuze 12).

Tests: 5 cases — happy, auth-401, demo-403, scope-404, already-archived-422.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

__tests__/actions/todos-promote-idea.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+const { mockSession } = vi.hoisted(() => ({
+  mockSession: { userId: 'user-1', isDemo: false },
+}))
+
+vi.mock('next/cache', () => ({ revalidatePath: vi.fn() }))
+vi.mock('next/headers', () => ({ cookies: vi.fn().mockResolvedValue({}) }))
+vi.mock('iron-session', () => ({
+  getIronSession: vi.fn().mockImplementation(async () => mockSession),
+}))
+vi.mock('@/lib/session', () => ({
+  sessionOptions: { cookieName: 'test', password: 'test-password-32-chars-minimum-len' },
+}))
+vi.mock('@/lib/idea-code-server', () => ({
+  nextIdeaCode: vi.fn().mockResolvedValue('IDEA-005'),
+}))
+vi.mock('@/lib/product-access', () => ({
+  productAccessFilter: vi.fn().mockReturnValue({}),
+}))
+vi.mock('@/lib/code-server', () => ({
+  generateNextPbiCode: vi.fn(),
+  generateNextStoryCode: vi.fn(),
+}))
+vi.mock('@/lib/rate-limit', () => ({
+  enforceUserRateLimit: vi.fn().mockReturnValue(null),
+}))
+vi.mock('@/lib/prisma', () => ({
+  prisma: {
+    todo: {
+      findFirst: vi.fn(),
+      update: vi.fn(),
+    },
+    idea: {
+      create: vi.fn(),
+    },
+    ideaLog: { create: vi.fn() },
+    $transaction: vi.fn(),
+  },
+}))
+
+import { prisma } from '@/lib/prisma'
+import { promoteTodoToIdeaAction } from '@/actions/todos'
+
+type M = {
+  todo: { findFirst: ReturnType<typeof vi.fn>; update: ReturnType<typeof vi.fn> }
+  idea: { create: ReturnType<typeof vi.fn> }
+  ideaLog: { create: ReturnType<typeof vi.fn> }
+  $transaction: ReturnType<typeof vi.fn>
+}
+const m = prisma as unknown as M
+
+beforeEach(() => {
+  vi.clearAllMocks()
+  mockSession.userId = 'user-1'
+  mockSession.isDemo = false
+  m.$transaction.mockImplementation(async (arg: unknown) => {
+    if (typeof arg === 'function') {
+      return (arg as (tx: unknown) => unknown)(m)
+    }
+    return arg
+  })
+})
+
+describe('promoteTodoToIdeaAction', () => {
+  it('happy: archives todo, creates DRAFT idea, returns idea_id', async () => {
+    m.todo.findFirst.mockResolvedValueOnce({
+      id: 'todo-1',
+      title: 'My idea',
+      description: 'desc',
+      product_id: null,
+      archived: false,
+    })
+    m.idea.create.mockResolvedValueOnce({ id: 'idea-9', code: 'IDEA-005' })
+
+    const r = await promoteTodoToIdeaAction('todo-1')
+    expect(r).toMatchObject({ success: true, idea_id: 'idea-9', idea_code: 'IDEA-005' })
+    expect(m.todo.update).toHaveBeenCalledWith({
+      where: { id: 'todo-1' },
+      data: { archived: true },
+    })
+  })
+
+  it('rejects unauthenticated', async () => {
+    mockSession.userId = ''
+    const r = await promoteTodoToIdeaAction('todo-1')
+    expect(r).toMatchObject({ code: 401 })
+  })
+
+  it('rejects demo-user', async () => {
+    mockSession.isDemo = true
+    const r = await promoteTodoToIdeaAction('todo-1')
+    expect(r).toMatchObject({ code: 403 })
+  })
+
+  it('returns 404 when todo belongs to another user', async () => {
+    m.todo.findFirst.mockResolvedValueOnce(null)
+    const r = await promoteTodoToIdeaAction('todo-1')
+    expect(r).toMatchObject({ code: 404 })
+  })
+
+  it('rejects already-archived todo', async () => {
+    m.todo.findFirst.mockResolvedValueOnce({
+      id: 'todo-1',
+      title: 'x',
+      description: null,
+      product_id: null,
+      archived: true,
+    })
+    const r = await promoteTodoToIdeaAction('todo-1')
+    expect(r).toMatchObject({ code: 422 })
+    expect(m.idea.create).not.toHaveBeenCalled()
+  })
+})