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/03-reference/03-template-variables.md

@@ -211,6 +211,27 @@ MD5 hash of page-specific CSS for cache busting.
 **Optional:** Only set if `$pageCssUrl` exists  
 **Example:** See `$pageCssUrl` above
 
+### `$pageJsUrl`
+
+URL to page-specific JavaScript file.
+
+**Type:** String (URL)  
+**Optional:** Only set if `script.js` exists in content directory  
+**Example:**
+```php
+<?php if (!empty($pageJsUrl)): ?>
+  <script defer src="<?= htmlspecialchars($pageJsUrl) ?>?v=<?= htmlspecialchars($pageJsHash ?? '') ?>"></script>
+<?php endif; ?>
+```
+
+### `$pageJsHash`
+
+MD5 hash of page-specific JavaScript for cache busting.
+
+**Type:** String (MD5 hash)  
+**Optional:** Only set if `$pageJsUrl` exists  
+**Example:** See `$pageJsUrl` above
+
 ### `$feedUrl`
 
 URL to the Atom feed for the current list page.
@@ -415,6 +436,8 @@ Then use in templates:
 | `$translations` | ✓ | — | — |
 | `$pageCssUrl` | ✓ | — | — |
 | `$pageCssHash` | ✓ | — | — |
+| `$pageJsUrl` | ✓ | — | — |
+| `$pageJsHash` | ✓ | — | — |
 | `$feedUrl` | ✓ | — | — |
 | `$metadata` | — | ✓ | ✓ |
 | `$pageContent` | — | — | ✓ |