[davide-pi]

Fixes #1181

• I have read the Contribution Guidelines
• I have checked that there isn't already another pull request that solves the above issue
• All newly added code is adequately covered by tests
• All existing tests are still running without errors

AI disclosure: Claude Code was used to investigate the issue and draft the fix and test; changes were reviewed and verified locally.

Changes

TextPrompt interpolated the default value into the prompt markup without escaping it, so values containing brackets (e.g. root['config'][0]) threw an InvalidOperationException. The default value, masked or not, is now escaped before being written.

Added a test covering a default value with brackets.

Note: AnsiConsoleTests+Size.Should_Not_Throw_When_Live_Display_Overflows_And_Output_Reports_Negative_Height fails on main as well, independently of this change.

[davide-pi]

The Build failure is unrelated to this change: NuGet audit errors on SixLabors.ImageSharp 3.1.12 currently break every PR build. Details in #2235.

[patriksvensson]

@davide-pi Yeah, I will need to solve this asap. We probably need to move the imagesharp addin to a separate repository and update to version 4 due to how licensing works.