Add savings chat analysis feature

src/components/charts/categoryBreakdownData.ts

@@ -0,0 +1,17 @@
+export type CategoryBreakdownItem = {
+  name: string;
+  amount: number;
+  color: string;
+  block?: "wiederkehrend" | "variabel";
+};
+
+export type CategoryPieItem = CategoryBreakdownItem & {
+  chartAmount: number;
+};
+
+export function toCategoryPieData(data: CategoryBreakdownItem[]): CategoryPieItem[] {
+  return data.map((item) => ({
+    ...item,
+    chartAmount: Math.abs(item.amount),
+  }));
+}