feat: complete ShiftCraft — AI-powered shift scheduling SaaS

Complete implementation including:
- Landing page with hero, features, how-it-works, pricing
- Employee management (CRUD with soft delete)
- AI constraint parser (Anthropic Claude API)
- German labor law templates (ArbZG §3, §5, §9)
- HiGHS ILP solver for optimal fair schedules
- Schedule calendar result view (employee × date grid)
- Shift framework configuration (periods + shifts)
- Subscription tiers: Free / Pro / Business
- PocketBase setup script with collection creation + seed data
- .env.example with all required variables documented

Pages: employees, constraints (list/new/templates), schedules (list/new/[id]),
       settings (organization/shifts/billing), dashboard

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

shared/types/schedule.ts

@@ -0,0 +1,59 @@
+export interface ShiftAssignment {
+  employee_id: string
+  employee_name: string
+  shift_id: string
+  shift_name: string
+  period_id: string
+  date: string // ISO date
+  start_time: string
+  end_time: string
+}
+
+export interface SolveResult {
+  status: 'solved' | 'infeasible' | 'error'
+  assignments: ShiftAssignment[]
+  objective_value?: number
+  duration_ms?: number
+  infeasibility_hints?: Array<{ constraint_id?: string; description: string }>
+}
+
+export interface SolveInput {
+  organization_id: string
+  period_start: string
+  period_end: string
+  framework: {
+    periods: Period[]
+    shifts: Shift[]
+  }
+  employees: Employee[]
+  constraints: Array<{ id: string; constraint_json: import('./constraint').ConstraintJSON; hard: boolean; weight?: number }>
+}
+
+export interface Period {
+  id: string
+  name: string
+  start_time: string
+  end_time: string
+  color: string
+}
+
+export interface Shift {
+  id: string
+  period_id: string
+  name: string
+  duration_hours: number
+  workers_required: number
+  days_applicable: number[] // 0=Mon...6=Sun, empty = all days
+}
+
+export interface Employee {
+  id: string
+  name: string
+  roles: string[]
+  skills: string[]
+  employment_type: 'full_time' | 'part_time' | 'mini_job'
+  weekly_hours_target: number
+  max_weekly_hours: number
+  available_periods: string[]
+  unavailable_dates: string[]
+}