feat: initialize monorepo structure with Bun and Turborepo

- Add package.json for the root with workspace configuration and scripts
- Create @gruperly/config package with TypeScript configuration
- Establish shared package @gruperly/shared with Zod schemas for validation
- Implement group, student, and payment schemas using Zod
- Set up TypeScript configuration for shared package
- Document stack architecture and technical specifications in stack.md
- Configure Turborepo with build, dev, lint, and typecheck tasks

apps/web/src/router.tsx

@@ -0,0 +1,49 @@
+import { createRootRoute, createRoute, createRouter } from '@tanstack/react-router'
+import { RootLayout } from './components/layout'
+import { HomeView } from './routes/home'
+import { GroupsView } from './routes/groups'
+import { PaymentsView } from './routes/payments'
+import { SettingsView } from './routes/settings'
+
+const rootRoute = createRootRoute({
+  component: RootLayout,
+})
+
+const indexRoute = createRoute({
+  getParentRoute: () => rootRoute,
+  path: '/',
+  component: HomeView,
+})
+
+const groupsRoute = createRoute({
+  getParentRoute: () => rootRoute,
+  path: '/groups',
+  component: GroupsView,
+})
+
+const paymentsRoute = createRoute({
+  getParentRoute: () => rootRoute,
+  path: '/payments',
+  component: PaymentsView,
+})
+
+const settingsRoute = createRoute({
+  getParentRoute: () => rootRoute,
+  path: '/settings',
+  component: SettingsView,
+})
+
+const routeTree = rootRoute.addChildren([
+  indexRoute,
+  groupsRoute,
+  paymentsRoute,
+  settingsRoute,
+])
+
+export const router = createRouter({ routeTree })
+
+declare module '@tanstack/react-router' {
+  interface Register {
+    router: typeof router
+  }
+}