Updated the `ContentTemplate` to enhance the layout of the
`#attachment-content` container by using `display: flex` and
ensuring full height utilization. Added CSS rules for consistent
styling of the `.CodeMirror` editor, including font size and
height adjustments.
Simplified CodeMirror initialization for XML files by removing
redundant `<textarea>` creation and directly embedding the
editor. Added `viewportMargin: Infinity` for better rendering
and used `setTimeout` to ensure proper sizing and refresh.
Refined plain text rendering for non-XML files to maintain a
clean and consistent display.
f7cac8c0a7