refactor: migrate UI to Preact components and remove legacy Astro/JS

- Replaced all .astro components with .jsx Preact components and added corresponding CSS modules.
- Updated index.astro to use the new App Preact component; removed legacy script and Astro imports.
- Deleted obsolete .astro component files and main JS logic (src/scripts/index.js, public/scripts/index.js).
- Updated astro.config.mjs for Preact integration.
- Updated package.json and package-lock.json to include @astrojs/preact and preact.
- Updated tsconfig.json for Preact JSX support.
- Refactored index.css to keep only global resets and utility styles.
- All changes relate to Gitea issue #1 (refactor to astro app).

Migrates the UI from Astro/vanilla JS to a modular Preact component architecture, removing all legacy code and aligning the project with modern best practices.
Refs #1

src/components/GameList.module.css

@@ -0,0 +1,46 @@
+.screen.active {
+    display: block;
+    opacity: 1;
+    transform: translateX(0);
+    position: relative;
+}
+.screen-content {
+    display: flex;
+    flex-direction: column;
+    min-height: 100vh;
+    padding: 20px;
+    overflow-y: auto;
+    -webkit-overflow-scrolling: touch;
+}
+.screen-title {
+    font-size: 24px;
+    margin-bottom: 20px;
+}
+.game-list {
+    width: 100%;
+    flex: 1;
+    overflow-y: auto;
+}
+.nav-buttons {
+    display: flex;
+    flex-direction: column;
+    gap: 10px;
+    margin: 20px 0 40px 0;
+}
+.btn {
+    flex: 1;
+    min-width: 100px;
+    padding: 20px;
+    color: white;
+    border: none;
+    border-radius: 0;
+    font-size: 20px;
+    cursor: pointer;
+    touch-action: manipulation;
+}
+.filter-button {
+    background: #333;
+}
+.filter-button.active {
+    background: #4CAF50;
+}