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

app/(dashboard)/business/proposals/page.tsx

@@ -0,0 +1,41 @@
+import { createClient } from "@/lib/supabase/server";
+import { ProposalsClient, type ProposalRow } from "./proposals-client";
+
+export default async function ProposalsPage() {
+  const supabase = await createClient();
+  const { data: { user } } = await supabase.auth.getUser();
+
+  if (!user) {
+    return null;
+  }
+
+  const { data: proposalsData } = await supabase
+    .from("proposals")
+    .select(`
+      id,
+      title,
+      amount,
+      currency,
+      status,
+      valid_until,
+      created_at,
+      clients ( name ),
+      projects ( name )
+    `)
+    .eq("user_id", user.id)
+    .order("created_at", { ascending: false });
+
+  const proposals: ProposalRow[] = (proposalsData || []).map((p: any) => ({
+    id: p.id,
+    title: p.title,
+    amount: Number(p.amount),
+    currency: p.currency,
+    status: p.status,
+    valid_until: p.valid_until,
+    created_at: p.created_at,
+    clientName: p.clients?.name || null,
+    projectName: p.projects?.name || null,
+  }));
+
+  return <ProposalsClient proposals={proposals} />;
+}