Describe the Bug

The Java bridge glue is injected at URL fetch time to support injecting the glue into navigated-to pages.
The detection of which fetches to inject the glue into is based on file mime type detection, but handlebars doesn't have a registered mime type and get returned as HTML, so has glue injected that are invalid handlebars.

To Reproduce

Use the AddOn in https://gitlab.com/richardmaw/maptool-bar-test/ with the properties and set a token to the Bars stat sheet.

Observe no stat sheet is rendered and the console logs an exception.

Expected Behaviour

Stat sheet renders.

Screenshots

No response

MapTool Info

develop

Desktop

No response

Additional Context

Likely broken since #5461, #5489 fixed other types of file.