Fix cashflow null category rows (#382)

## Sentry
- Issue: PHP-LARAVEL-1T
- URL: https://whisper-money.sentry.io/issues/PHP-LARAVEL-1T

## Root cause
Cashflow breakdown UI assumed every API row has a category object.
Production returned a breakdown row with `category: null`, so rendering
read `item.category.icon` and crashed.

## Fix
- Allow breakdown rows to carry nullable category/category_id.
- Render null categories as Uncategorized with HelpCircle/gray fallback.
- Add focused Vitest regression.
- Enable Wayfinder Vite plugin in Vitest so components importing
generated actions resolve in tests.

## Verification
- `npm test -- resources/js/components/cashflow/breakdown-card.test.tsx`
- `npx prettier --write
resources/js/components/cashflow/breakdown-card.tsx
resources/js/components/cashflow/breakdown-card.test.tsx
resources/js/hooks/use-cashflow-data.ts vitest.config.ts`
- `npx eslint resources/js/components/cashflow/breakdown-card.tsx
resources/js/components/cashflow/breakdown-card.test.tsx
resources/js/hooks/use-cashflow-data.ts vitest.config.ts --fix`

## Notes
- `npm run types` currently fails on existing unrelated TypeScript
errors across account, transaction, chart, auth, crypto, and dexie
files.

resources/js/components/cashflow/breakdown-card.test.tsx

@@ -0,0 +1,48 @@
+import { render, screen } from '@testing-library/react';
+import type React from 'react';
+import { describe, expect, it, vi } from 'vitest';
+import { BreakdownCard } from './breakdown-card';
+
+vi.mock('@/components/ui/amount-display', () => ({
+    AmountDisplay: ({ amountInCents }: { amountInCents: number }) => (
+        <span>{amountInCents}</span>
+    ),
+}));
+
+vi.mock('@/actions/App/Http/Controllers/TransactionController', () => ({
+    index: () => ({ url: '/transactions' }),
+}));
+
+vi.mock('@inertiajs/react', () => ({
+    Link: ({ children, href }: { children: React.ReactNode; href: string }) => (
+        <a href={href}>{children}</a>
+    ),
+    usePage: () => ({ props: { chartColorScheme: 'colorful' } }),
+}));
+
+describe('BreakdownCard', () => {
+    it('renders uncategorized rows when the API returns a null category', () => {
+        render(
+            <BreakdownCard
+                type="expense"
+                data={{
+                    data: [
+                        {
+                            category: null,
+                            category_id: null,
+                            amount: 12345,
+                            percentage: 100,
+                            previous_amount: 0,
+                        },
+                    ],
+                    total: 12345,
+                    previous_total: 0,
+                }}
+                currency="USD"
+            />,
+        );
+
+        expect(screen.getByText('Uncategorized')).toBeInTheDocument();
+        expect(screen.getByText('100%')).toBeInTheDocument();
+    });
+});

resources/js/components/cashflow/breakdown-card.tsx

@@ -12,7 +12,11 @@ import { Progress } from '@/components/ui/progress';
 import { BreakdownData } from '@/hooks/use-cashflow-data';
 import { useChartColors } from '@/hooks/use-chart-color-scheme';
 import { cn } from '@/lib/utils';
-import { getCategoryColorClasses } from '@/types/category';
+import {
+    type CategoryColor,
+    type CategoryIcon,
+    getCategoryColorClasses,
+} from '@/types/category';
 import { __ } from '@/utils/i18n';
 import { Link } from '@inertiajs/react';
 import { format } from 'date-fns';
@@ -27,6 +31,12 @@ interface BreakdownCardProps {
     period?: { from: Date; to: Date };
 }
 
+const fallbackCategory = {
+    name: __('Uncategorized'),
+    icon: 'HelpCircle' as CategoryIcon,
+    color: 'gray' as CategoryColor,
+};
+
 export function BreakdownCard({
     type,
     data,
@@ -89,8 +99,9 @@ export function BreakdownCard({
             <CardContent>
                 <div className="space-y-4">
                     {data.data.map((item, index) => {
+                        const category = item.category ?? fallbackCategory;
                         const Icon = (Icons[
-                            item.category.icon as keyof typeof Icons
+                            category.icon as keyof typeof Icons
                         ] || Icons.HelpCircle) as LucideIcon;
 
                         const percentageChange =
@@ -101,10 +112,10 @@ export function BreakdownCard({
                                 : null;
 
                         const categoryColor = getCategoryColorClasses(
-                            item.category.color,
+                            category.color,
                         );
                         const chartColor = categoryBarColor(
-                            item.category.color,
+                            category.color,
                             index,
                         );
 
@@ -134,7 +145,7 @@ export function BreakdownCard({
                                             <Icon className="size-3.5" />
                                         </div>
                                         <span className="min-w-0 truncate text-sm font-medium">
-                                            {item.category.name}
+                                            {category.name}
                                         </span>
                                     </div>
                                     <div className="flex gap-2">

resources/js/hooks/use-cashflow-data.ts

@@ -30,8 +30,8 @@ export interface TrendDataPoint {
 }
 
 export interface BreakdownItem {
-    category: Category;
-    category_id: string;
+    category: Category | null;
+    category_id: string | null;
     amount: number;
     percentage: number;
     previous_amount: number;

vitest.config.ts

@@ -1,9 +1,10 @@
+import { wayfinder } from '@laravel/vite-plugin-wayfinder';
 import react from '@vitejs/plugin-react';
 import { resolve } from 'path';
 import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
-    plugins: [react()],
+    plugins: [react(), wayfinder({ formVariants: true })],
     test: {
         environment: 'jsdom',
         globals: true,