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/components/brand/LogoIcon.tsx

@@ -0,0 +1,39 @@
+import { forwardRef, type SVGProps } from 'react'
+import { cn } from '../../lib/utils'
+
+export type LogoIconProps = SVGProps<SVGSVGElement> & {
+  className?: string
+}
+
+export const LogoIcon = forwardRef<SVGSVGElement, LogoIconProps>(
+  ({ className, ...props }, ref) => {
+    return (
+      <svg
+        ref={ref}
+        viewBox="0 0 40 40"
+        fill="none"
+        role="img"
+        aria-label="Gruperly"
+        className={cn('size-8', className)}
+        {...props}
+      >
+        <rect
+          width="40"
+          height="40"
+          rx="10"
+          className="fill-accent-soft"
+        />
+        <path
+          d="M17 14.5c0-1.4 3-1.4 3 0V27.5c0 3-2.5 6-6.5 6-3.6 0-6-2.1-6-5 0-1.4 3-1.4 3 0 0 1 .6 2 3 2 2 0 3-1.2 3-3V17z"
+          className="fill-accent"
+        />
+        <path
+          d="M20 15.5c0-1.4 3-1.4 3 0v6c0 3 2 5 5.5 5 1.4 0 3-1.2 3-3 0-1.4 3-1.4 3 0 0 3-2.6 4.6-6.5 4.6-4 0-5-3-5-6.6v-6z"
+          className="fill-accent"
+        />
+      </svg>
+    )
+  },
+)
+
+LogoIcon.displayName = 'LogoIcon'