fix(shared): tag filter SQL precedence, balance cards filter by tag

src/app/api/participants/balances/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 balances = await getParticipantBalances(user.id);
+  const tagParam = req.nextUrl.searchParams.get("tag_ids");
+  const tagIds = tagParam ? tagParam.split(",").map(Number).filter(Boolean) : undefined;
+  const balances = await getParticipantBalances(user.id, tagIds);
   return NextResponse.json(balances);
 }

src/app/shared/page.tsx

@@ -259,7 +259,7 @@ function PaymentHistory({ participantId, currentUserId }: { participantId: numbe
 export default function SharedPage() {
   const [tagIds, setTagIds] = useState<string[]>([]);
   const { data: transactions = [], isLoading: txLoading } = useSharedTransactions(tagIds);
-  const { data: balances = [], isLoading: balLoading } = useParticipantBalances();
+  const { data: balances = [], isLoading: balLoading } = useParticipantBalances(tagIds);
   const { data: me } = useCurrentUser();
   const [addingParticipant, setAddingParticipant] = useState(false);
   const [paymentModal, setPaymentModal] = useState<{ id: number; name: string; balance: number } | null>(null);