This is a massive project. Let me set up a task list and start building systematically.

Now let me start building. First, I'll create the data layer with types and demo data, then update the theme.

Now let me create the store and update the theme:

Now let me build the app shell with sidebar, header, and role switcher. Let me first check the sidebar component:

Good, I have all the context I need. Now let me build the app shell - the AppProvider, sidebar nav, header, and the main layout:

Now let me update the layout and create the main page with phase routing:

Now let me create all the phase components. I'll start with Dashboard and Preparation:

Now let me build the Resources phase with tabs for Teachers, Rooms, Subjects, and Classes:

Now let me build the Constraints and Timetable Drafting phases:

Now the timetable drafting phase with drag & drop and generation simulation:

Now let me create the main page that ties everything together:

Now let me update the font configuration in the globals.css to use the Inter variable:

The full Stundenplanung der Zukunft prototype is now complete. Here's what was built across all 6 planning phases:

Architecture: In-memory mock data store with React context, component-based architecture with a sidebar navigation shell, header with role switcher, and phase-based routing -- all using Next.js App Router with Tailwind and shadcn/ui components.

Key Features:

• Dashboard -- Overview stats, planning progress, conflict summary, draft versions, and quick-action shortcuts
• Vorbereitung (Preparation) -- Holiday/special-day management (CRUD) and time grid display with German period structure
• Ressourcen (Resources) -- Tabbed view for 10 teachers (with workload bars and CSV import mock), 12 subjects (with per-class hour matrix), 8 rooms (cards with equipment), and 6 classes
• Bedingungen (Constraints) -- Interactive per-teacher availability grid (click to toggle) and preference settings for preferred/avoided time slots
• Stundenplanung (Drafting) -- Full weekly timetable grid with drag-and-drop reordering, "Generate Timetable" simulation, conflict highlighting in red, multi-class parallel planning view, and a disabled KI-Optimierung button as a future-feature placeholder
• Konflikterkennung (Conflicts) -- Conflict list with severity badges, type icons, resolve/reopen actions, and navigation to the timetable view
• Finalisierung (Finalization) -- Draft versioning (create new versions), PDF export mock, audit log table, and future feature placeholders (AI optimization, scenario comparison, substitute planning, analytics)