Favicons and logos
Bear has a favicon attribute on the home page which supports either an emoji or a url parameter for setting the favicon. This has general support across browsers. Eg:
favicon: https://example.com/logo.png
or
favicon: 🐻
If you would like more granular control over the rendering of the favicon (for things like bookmarks and search), you can manually create and upload the various sizes of favicons and add them to the Head directive in Settings. Eg:
<!-- Icons -->
<link rel="apple-touch-icon" type="image/png" href="https://example.com/logo_180x180.png">
<link rel="icon" type="image/png" sizes="32x32" href="https://example.com/logo_32x32.png">
<link rel="icon" type="image/png" sizes="16x16" href="https://example.com/logo_16x16.png">
<link rel="shortcut icon" href="https://example.com/logo.png">
Note that browsers, search engines, and other tools that use favicons have very aggressive caching, so updates will not show on a device you've previously used to view the favicon. I recommend inspecting favicon updates using a tool like Real Favicon.