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
 ```
 

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` | — | — | ✓ |

docs/04-development/02-content-system.md

@@ -126,6 +126,12 @@ Checks extensions in `COVER_IMAGE_EXTENSIONS` order: `jpg`, `jpeg`, `png`, `webp
 
 Returns `['url' => string, 'hash' => string]` or null. Hash is MD5 of file content for cache busting.
 
+## Page-Specific JavaScript
+
+**`findPageJs(string $dirPath, string $contentDir): ?array`** — Checks for `script.js` in content directory.
+
+Returns `['url' => string, 'hash' => string]` or null. Hash is MD5 of file content for cache busting. The script is loaded with the `defer` attribute in `base.php`, placed before `</body>` for non-blocking progressive enhancement.
+
 ## Meta Description Extraction
 
 **`extractMetaDescription(string $dirPath, ?array $metadata): ?string`**

docs/04-development/06-templates.md

@@ -59,6 +59,8 @@ Variables are injected via `extract()` — each array key becomes a local variab
 | `$homeLabel` | string | yes | Home link text |
 | `$pageCssUrl` | ?string | no | Page-specific CSS URL |
 | `$pageCssHash` | ?string | no | CSS cache-bust hash |
+| `$pageJsUrl` | ?string | no | Page-specific JS URL |
+| `$pageJsHash` | ?string | no | JS cache-bust hash |
 | `$feedUrl` | ?string | no | Atom feed URL (only on lists with `feed = true`) |
 | `$currentLang` | string | plugin | Language code (from languages plugin) |
 | `$langPrefix` | string | plugin | URL language prefix |

docs/04-development/07-rendering.md

@@ -23,7 +23,7 @@ Used for both frontpage and page views:
 1. Load metadata for `$pageDir`
 2. Load page plugins (from metadata `plugins` field)
 3. Render all content files, concatenate HTML
-4. Compute: `$pageTitle`, `$metaDescription`, `$pageCssUrl`/`$pageCssHash`, `$socialImageUrl`
+4. Compute: `$pageTitle`, `$metaDescription`, `$pageCssUrl`/`$pageCssHash`, `$pageJsUrl`/`$pageJsHash`, `$socialImageUrl`
 5. Fire `Hook::TEMPLATE_VARS` with all variables
 6. `extract()` variables → render `page.php` → capture output as `$content`
 7. Render `base.php` with `$content` + base variables
@@ -37,12 +37,12 @@ Handled directly in `router.php` (not a separate function):
 2. Load metadata, check `hide_list`
 3. Select list template from `page_template` metadata
 4. Call `buildListItems()` from `helpers.php` (builds + sorts items)
-5. Store `pageTitle`, `metaDescription`, `pageCssUrl`, `pageCssHash`, `feedUrl` on context
+5. Store `pageTitle`, `metaDescription`, `pageCssUrl`, `pageCssHash`, `pageJsUrl`, `pageJsHash`, `feedUrl` on context
 6. Fire `Hook::TEMPLATE_VARS`
 7. Render list template → capture as `$content`
 8. Pass to `renderTemplate()` which renders `base.php`
 
-**`renderTemplate(Context $ctx, string $content, int $statusCode = 200): void`** — Wraps content in base template. Used for list views and error pages. Reads `pageTitle`, `metaDescription`, `pageCssUrl`, `pageCssHash`, and `feedUrl` from the context object (set by the list case in `router.php`). For error pages, these context keys are unset, so base.php receives nulls.
+**`renderTemplate(Context $ctx, string $content, int $statusCode = 200): void`** — Wraps content in base template. Used for list views and error pages. Reads `pageTitle`, `metaDescription`, `pageCssUrl`, `pageCssHash`, `pageJsUrl`, `pageJsHash`, and `feedUrl` from the context object (set by the list case in `router.php`). For error pages, these context keys are unset, so base.php receives nulls.
 
 ## Atom Feed Rendering
 
@@ -79,9 +79,9 @@ setCachedMarkdown(string $filePath, string $html, string $langPrefix = ''): void
 
 Before content routing, the router serves static files from content directory with an explicit MIME type allowlist:
 
-`css`, `jpg`, `jpeg`, `png`, `gif`, `webp`, `svg`, `pdf`, `woff`, `woff2`, `ttf`, `otf`
+`css`, `jpg`, `jpeg`, `png`, `gif`, `webp`, `svg`, `pdf`, `woff`, `woff2`, `ttf`, `otf`, `js`
 
-Files not in this list are not served as static assets. Notably, `.js` files are excluded — JavaScript must be placed in `custom/assets/` to be served (at the document root URL), or linked from an external source.
+Files not in this list are not served as static assets.
 
 ### Custom Assets (router.php)
 
@@ -100,9 +100,9 @@ Files in `custom/assets/` are served at the document root URL. Example: `custom/
 
 MIME types resolved from extension map, falling back to `mime_content_type()`.
 
-## CSS Cache Busting
+## CSS and JS Cache Busting
 
-Page-specific CSS gets an MD5 hash appended: `?v={hash}`. Computed by `findPageCss()`. The default theme's CSS is linked directly without hash (uses browser caching).
+Page-specific CSS and JS get an MD5 hash appended: `?v={hash}`. Computed by `findPageCss()` and `findPageJs()` respectively. The default theme's CSS is linked directly without hash (uses browser caching).
 
 ## Parsedown