feat: Implement sidebar collapse and expand functionality

- Add CSS for collapsed sidebar state and transitions
- Introduce SidebarToggle class for managing collapse/expand logic
- Integrate SidebarToggle initialization in main script
- Add toggle button to navbar and make mini sidebar clickable
- Store sidebar collapsed state in localStorage
- Filter image files and directories in view mode via FileTree
- Make navbar brand clickable to navigate to collection root or home

static/js/utils.js

@@ -103,6 +103,31 @@ const PathUtils = {
         return binaryExtensions.includes(extension);
     },
 
+    /**
+     * Check if a directory is an image directory based on its name
+     * @param {string} path - The directory path
+     * @returns {boolean} True if the directory is for images
+     * @example PathUtils.isImageDirectory('images') // true
+     * @example PathUtils.isImageDirectory('assets/images') // true
+     * @example PathUtils.isImageDirectory('docs') // false
+     */
+    isImageDirectory(path) {
+        const dirName = PathUtils.getFileName(path).toLowerCase();
+        const imageDirectoryNames = [
+            'images',
+            'image',
+            'img',
+            'imgs',
+            'pictures',
+            'pics',
+            'photos',
+            'assets',
+            'media',
+            'static'
+        ];
+        return imageDirectoryNames.includes(dirName);
+    },
+
     /**
      * Get a human-readable file type description
      * @param {string} path - The file path