Add markdown.codeBlockIndent setting to customize indentation prefix for
rendered code blocks. Default remains 2 spaces for visual clarity, but
setting to empty string removes indentation for easier copy/paste of
code snippets to scripts, editors, or other tools.
Changes:
- tui: add optional codeBlockIndent to MarkdownTheme interface
- coding-agent: add MarkdownSettings with codeBlockIndent property
- coding-agent: compose theme with settings at call sites (no global state)
- coding-agent: update message components to accept optional MarkdownTheme
Co-authored-by: Mario Zechner <badlogicgames@gmail.com>
