[Bug]: Custom folder associations fail to render SVG icons from local extension paths (shows blank space)

### Describe the bug When trying to use the "material-icon-theme.folders.associations" setting to load custom user SVG icons from a local directory (such as .vscode/extensions/icons/), the extension successfully intercepts the targeted folder name (e.g., "src" or "folder"), completely hides the default icon, but fails to render the custom icon—leaving an empty blank space next to the folder name. This issue persists regardless of whether relative paths, absolute paths, or standard file:/// protocols are declared in settings.json. ### To Reproduce Steps to Reproduce Create a custom folder under the .vscode extensions path: C:\Users\<User>\.vscode\extensions\icons\ Place two valid SVG files inside labeled: my-folder.svg and my-folder-open.svg. Configure settings.json User Profile with the custom association: JSON "material-icon-theme.folders.associations": { "src": "C:/Users/<User>/.vscode/extensions/icons/my-folder" } Save settings and execute Developer: Reload Window. Observe the file tree sidebar layout. ### Expected behavior Expected Behavior The custom SVG graphics (my-folder.svg / my-folder-open.svg) should render cleanly in place of the default directory icons. Actual Behavior The default icon is hidden successfully, proving the extension reads the association rule, but the custom SVG container remains completely transparent/blank. ### Screenshots Screenshots <img width="799" height="102" alt="Image" src="https://github.com/user-attachments/assets/a6fc7be6-cdca-4e28-b3c4-c60f274934f8" /> ### Computer information Environment OS: Windows 11 / Windows 10 VS Code Version: 1.90+ Material Icon Theme Version: Latest ### Additional context _No response_ ### Code of Conduct - [x] I agree to follow this project's **Code of Conduct**