feat: complete Phase 1 foundation scaffold

- Monorepo: Turborepo + pnpm workspaces with 7 apps/packages
- Backend: NestJS scaffold with 9 modules (auth, tenant, curriculum, simulation, portfolio, ai-coach, analytics, classroom, gamification)
- Frontend: React 18 + Vite + TailwindCSS + shadcn/ui with 10 pages, 14 UI primitives, 3 Zustand stores
- Database: Prisma schema with 19 models, 13 enums, seed script, multi-tenant ready
- Docker: Dev, production, and Portainer Compose files with Traefik reverse proxy
- Configuration: .env.example (47 vars), Zod validation, frontend-safe env exposure
- i18n: English + Greek locale files (10 files), ICU MessageFormat, react-i18next
- Shared packages: @investplay/types, @investplay/ui, @investplay/i18n, @investplay/utils
- CI/CD: GitHub Actions (lint, typecheck, test, build, deploy, PR checks)
- Documentation: CONTEXT.md, ARCHITECTURE.md (10 Mermaid diagrams), API.md, LOCALIZATION.md, DEVELOPMENT-ROADMAP.md
- Infrastructure: Dockerfiles (dev + prod), nginx configs, backup/healthcheck scripts
- Security: JWT auth guards, role-based access, rate limiting, Helmet, CORS, PII sanitization

apps/web/src/components/shared/EmptyState.tsx

@@ -0,0 +1,45 @@
+import { cn } from "@investplay/ui";
+import { Button } from "@/components/ui/button";
+import { Inbox } from "lucide-react";
+
+interface EmptyStateProps {
+  icon?: React.ReactNode;
+  title: string;
+  description?: string;
+  actionLabel?: string;
+  onAction?: () => void;
+  className?: string;
+}
+
+export function EmptyState({
+  icon,
+  title,
+  description,
+  actionLabel,
+  onAction,
+  className,
+}: EmptyStateProps) {
+  return (
+    <div
+      className={cn(
+        "flex flex-col items-center justify-center rounded-xl border border-dashed border-border p-12 text-center",
+        className,
+      )}
+    >
+      <div className="mb-4 text-muted-foreground">
+        {icon ?? <Inbox className="h-12 w-12" />}
+      </div>
+      <h3 className="text-lg font-semibold">{title}</h3>
+      {description && (
+        <p className="mt-1 max-w-sm text-sm text-muted-foreground">
+          {description}
+        </p>
+      )}
+      {actionLabel && onAction && (
+        <Button onClick={onAction} className="mt-4">
+          {actionLabel}
+        </Button>
+      )}
+    </div>
+  );
+}