Add page-specific JavaScript support

Update documentation for new JS variables and rendering pipeline

Add script.js file support to content directories

Implement cache-busting for JavaScript files

Update static file serving to include JavaScript files

Document page-specific script loading in base.php

docs/02-tutorial/02-styling.md

@@ -241,6 +241,33 @@ FolderWeb automatically loads and includes page-specific styles with cache-busti
 <link rel="stylesheet" href="/portfolio/styles.css?v=abc123def">
 ```
 
+## Page-Specific Scripts
+
+For small progressive enhancements, you can add a `script.js` file to a content directory:
+
+```
+content/portfolio/
+├── index.md
+├── styles.css
+└── script.js
+```
+
+**script.js:**
+```js
+// Small enhancement for this page only
+document.querySelector('.portfolio-grid')?.addEventListener('click', (e) => {
+  // ...
+});
+```
+
+FolderWeb automatically loads the script with `defer` (non-blocking) and cache-busting:
+
+```html
+<script defer src="/portfolio/script.js?v=abc123def"></script>
+```
+
+The script tag is placed before `</body>`, so it runs after the page has been parsed. This is ideal for progressive enhancement — the page works without JavaScript, but gets enhanced when it's available.
+
 ## Dark Mode
 
 Add dark mode with CSS variables and `prefers-color-scheme`:

docs/02-tutorial/03-templates.md

@@ -128,6 +128,10 @@ Let's modify `base.php` to add your site name and custom navigation:
       <small>Generated in <?= number_format($pageLoadTime, 4) ?>s</small>
     </p>
   </footer>
+
+  <?php if (!empty($pageJsUrl)): ?>
+    <script defer src="<?= htmlspecialchars($pageJsUrl) ?>?v=<?= $pageJsHash ?? '' ?>"></script>
+  <?php endif; ?>
 </body>
 </html>
 ```
@@ -301,6 +305,7 @@ $languageUrls     // Links to other language versions
 $translations     // Translated UI strings
 $cssHash          // Cache-busting hash for CSS
 $pageCssUrl       // Page-specific CSS URL (if exists)
+$pageJsUrl        // Page-specific JS URL (if exists)
 $pageLoadTime     // Page generation time
 ```