feat(profitability): set default period to this_month on omnichannel margin page

Co-authored-by: Your Name <you@example.com>
Reviewed-on: #13

apps/admin/src/pages/profitability/OmnichannelMarginPage.tsx

@@ -107,7 +107,7 @@ export default function OmnichannelMarginPage() {
   // Filters
   const [search, setSearch] = useState('');
   const [channelFilter, setChannelFilter] = useState<'all' | 'shopee' | 'lazada' | 'tiktok'>('all');
-  const [dateFilter, setDateFilter] = useState<DateFilterState>({ period: 'all' });
+  const [dateFilter, setDateFilter] = useState<DateFilterState>({ period: 'this_month' });
   const [sortBy, setSortBy] = useState('revenue_desc');
 
   const fetchData = async () => {

apps/backend/src/routes/profitability.ts

@@ -295,7 +295,7 @@ export const profitabilityRoute = new Elysia({ prefix: "/profitability" })
   .get("/omnichannel", async ({ query }) => {
     const search = (query.search || "").trim().toLowerCase();
     const channel = (query.channel || "all").trim().toLowerCase();
-    const dateRange = resolveDateRange(query.period, query.startDate, query.endDate);
+    const dateRange = resolveDateRange(query.period || "this_month", query.startDate, query.endDate);
 
     // 1. Fetch mapped marketplace products with master variants & BOM
     const mpProducts = await prisma.marketplaceProduct.findMany({