Phase 6: Plan-Ansicht — solution list + weekly grid view

Frontend additions in studio-v2:
  - types.ts adds TimetableSolution, TimetableLesson, SolutionStatus,
    CreateTimetableSolution mirroring the Go models.
  - lib/stundenplan/api.ts adds solutionsApi with list/get/create/remove/
    lessons. Solve trigger is POST /timetable/solutions — school-service
    forwards to the solver-service over the Docker network.
  - _components/plan/SolutionList: table of past solves with status
    badges, hard/soft score, Anzeigen + Loeschen buttons, and a
    'Neuen Plan generieren' trigger. Auto-polls every 4 s while any
    solution is pending/running, clears the interval otherwise.
  - _components/plan/PlanView: Mo–Fr × period weekly grid. Three
    perspectives (Klasse / Lehrer / Raum) toggleable via test-id'd
    buttons; selector below lists every unique resource with at least
    one lesson. Cells colour-coded by tt_subject.color.
  - _components/plan/PlanHub orchestrates list + view; default tab in
    page.tsx switches from 'klassen' to 'plan'.

Tests:
  - mockSchoolApi helper extracted to e2e/_helpers.ts so the spec file
    stays under 500 LOC. Helper now also mocks /solutions GET/POST/DELETE
    and /solutions/:id/lessons; solutions kept in a closure so POST
    appears in the next GET.
  - 8 new tests across two suites: SolutionList empty state, list
    render, completed-vs-failed Anzeigen visibility, solve trigger;
    PlanView placeholder when no selection, grid render, perspective
    switching.
  - Existing Klassen CRUD tests now click the Klassen tab first
    (Plan is the new default landing tab).

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

studio-v2/app/stundenplan/page.tsx

@@ -13,11 +13,13 @@ import { PeriodsManager } from './_components/PeriodsManager'
 import { CurriculumManager } from './_components/CurriculumManager'
 import { AssignmentsManager } from './_components/AssignmentsManager'
 import { RegelnHub } from './_components/regeln/RegelnHub'
+import { PlanHub } from './_components/plan/PlanHub'
 import { setStundenplanToken, getStundenplanToken } from '@/lib/stundenplan/api'
 
-type Tab = 'klassen' | 'lehrer' | 'faecher' | 'raeume' | 'periods' | 'curriculum' | 'assignments' | 'regeln'
+type Tab = 'plan' | 'klassen' | 'lehrer' | 'faecher' | 'raeume' | 'periods' | 'curriculum' | 'assignments' | 'regeln'
 
 const TABS: { id: Tab; label: string }[] = [
+  { id: 'plan', label: 'Plan' },
   { id: 'klassen', label: 'Klassen' },
   { id: 'lehrer', label: 'Lehrer' },
   { id: 'faecher', label: 'Faecher' },
@@ -30,7 +32,7 @@ const TABS: { id: Tab; label: string }[] = [
 
 export default function StundenplanPage() {
   const { isDark } = useTheme()
-  const [tab, setTab] = useState<Tab>('klassen')
+  const [tab, setTab] = useState<Tab>('plan')
   const [token, setToken] = useState(getStundenplanToken())
 
   const handleSaveToken = () => {
@@ -108,6 +110,7 @@ export default function StundenplanPage() {
         </nav>
 
         <section>
+          {tab === 'plan' && <PlanHub />}
           {tab === 'klassen' && <KlassenManager />}
           {tab === 'lehrer' && <LehrerManager />}
           {tab === 'faecher' && <FaecherManager />}