🎨 Palette: [UX improvement] Set monospaced font for ExceptionPopup stacktraces

[awest813]

💡 What: The UX enhancement added a monospaced font (java.awt.Font.MONOSPACED) to the JTextPane elements within the ExceptionPopup dialogs.
🎯 Why: Exception stacktraces in variable-width fonts are notoriously difficult to read, as the text indentation and code structure are not preserved correctly. Using a monospaced font drastically improves the readability of Java stacktraces for end-users or developers diagnosing issues in the editor UI tools.
♿ Accessibility: Improves readability and visual layout of code/error text.
📸 Before/After: Before, error text was variable-width, mangling the indentation. Now, it aligns exactly like it does in a terminal or IDE.

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PR created automatically by Jules for task 6706355053595229712 started by @awest813

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