feat(treasury): separate receipts from income and fit finance on a phone

A receipt or payment only reduces the party balance, while an income or expense keeps both amounts. Finance screens stack into cards on a phone so the forms and lists stay readable.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/web/src/views/treasury/useTreasuryMobile.ts

@@ -0,0 +1,7 @@
+import { computed } from 'vue';
+import { Grid } from 'ant-design-vue';
+
+export function useTreasuryMobile() {
+  const screens = Grid.useBreakpoint();
+  return computed(() => !screens.value.md);
+}