Structural cleanup

- Rename src/store/ -> src/context/ (store implies Redux, this is React Context)
- Rename services/api.jsx -> api.js (file contains no JSX)
- Delete unused Vite boilerplate: src/assets/, App.css
- Update all imports accordingly

src/pages/HomePage.jsx

@@ -1,6 +1,6 @@
 import React, { useEffect, useState, useContext, useMemo, useCallback } from 'react';
 import { Virtuoso } from 'react-virtuoso';
-import { CardContext } from '../store/CardContext';
+import { CardContext } from '../context/CardContext';
 import { fetchCards, fetchCardImage } from '../services/api';
 import { useDebounce } from '../hooks/useDebounce';
 import CardRow from '../components/CardRow/CardRow';