fix(payment): crash on open due to amount.toFixed on numeric string

feat(shared): tag filter on shared transactions list

src/app/api/shared-transactions/route.ts

@@ -6,6 +6,8 @@ export async function GET(req: NextRequest) {
   const user = await getCurrentUser(req);
   if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
 
-  const transactions = await getSharedTransactions(user.id);
+  const tagParam = req.nextUrl.searchParams.get("tag_ids");
+  const tagIds = tagParam ? tagParam.split(",").map(Number).filter(Boolean) : undefined;
+  const transactions = await getSharedTransactions(user.id, tagIds);
   return NextResponse.json(transactions);
 }