add price history routes and implement modal hook; enhance MainLayout tests with default mock values

server.ts

@@ -17,6 +17,7 @@ import budgetRouter from './src/routes/budget.routes';
 import flyerRouter from './src/routes/flyer.routes';
 import recipeRouter from './src/routes/recipe.routes';
 import personalizationRouter from './src/routes/personalization.routes';
+import priceRouter from './src/routes/price.routes';
 import statsRouter from './src/routes/stats.routes';
 import gamificationRouter from './src/routes/gamification.routes';
 import systemRouter from './src/routes/system.routes';
@@ -138,6 +139,8 @@ app.use('/api/flyers', flyerRouter);
 app.use('/api/recipes', recipeRouter);
 // 9. Public personalization data routes (master items, etc.).
 app.use('/api/personalization', personalizationRouter);
+// 9.5. Price history routes.
+app.use('/api/price-history', priceRouter);
 // 10. Public statistics routes.
 app.use('/api/stats', statsRouter);