feat(PBI-59): API route GET /api/jobs/[id]/sub-tasks voor sprint task executions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/jobs/[id]/sub-tasks/route.ts

@@ -0,0 +1,39 @@
+import type { NextRequest } from 'next/server'
+import { getSession } from '@/lib/auth'
+import { prisma } from '@/lib/prisma'
+
+export async function GET(
+  _request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const session = await getSession()
+  if (!session.userId) {
+    return Response.json({ error: 'Niet ingelogd' }, { status: 401 })
+  }
+  const userId = session.userId
+  const { id } = await params
+
+  const job = await prisma.claudeJob.findFirst({
+    where: { id, user_id: userId },
+    select: { kind: true },
+  })
+
+  if (!job || job.kind !== 'SPRINT_IMPLEMENTATION') {
+    return Response.json([], { status: 200 })
+  }
+
+  const executions = await prisma.sprintTaskExecution.findMany({
+    where: { sprint_job_id: id },
+    include: { task: { select: { code: true, title: true } } },
+    orderBy: { order: 'asc' },
+  })
+
+  return Response.json(
+    executions.map(e => ({
+      id: e.id,
+      taskCode: e.task.code,
+      taskTitle: e.task.title,
+      status: e.status,
+    }))
+  )
+}