feat: implement Business OS modules for proposals, invoices, and subscriptions with database schema and UI components

config/sidebar.ts

@@ -8,6 +8,9 @@ import {
   MessageCircleHeart,
   Sparkles,
   Wallet,
+  FileText,
+  Receipt,
+  CreditCard,
 } from "lucide-react";
 
 export type SidebarNavItem = {
@@ -40,6 +43,14 @@ export const sidebarData: SidebarNavGroup[] = [
       { title: "Finans", href: "/finance", icon: Wallet },
     ],
   },
+  {
+    title: "BUSINESS OS",
+    items: [
+      { title: "Teklifler", href: "/business/proposals", icon: FileText },
+      { title: "Faturalar", href: "/business/invoices", icon: Receipt },
+      { title: "Abonelikler", href: "/business/subscriptions", icon: CreditCard },
+    ],
+  },
   {
     title: "KİŞİSEL",
     items: [{ title: "Günlük", href: "/journal", icon: BookOpenText }],