Configurable line ending convention for file writes

[cek]

Is your feature request related to a problem? Please describe.
On Windows, file-writing tools (replace_content, create_text_file, replace_symbol_body, etc.) produce CRLF line endings because CodeEditor._save_edited_file() opens files in text mode using the platform-default line ending. Projects that use LF line endings on Windows end up with mixed line endings after edits.

Describe the solution you'd like
A line_ending option in project.yml (with possible values: "lf", "crlf", "native"; default "native" for backwards compatibility, or similar).

Describe alternatives you've considered
Git-based workarounds: core.autocrlf=true or .gitattributes with * text=auto. These work but create friction (staging noise, hook conflicts, inconsistent behavior across tools).

Additional context
I believe the changes required would be quite small in scope:

• CodeEditor._save_edited_file() (code_editor.py:76): pass newline= to open()
• CreateTextFileTool.apply() (tools/file_tools.py:76): pass newline= to Path.write_text()

[opcode81]

So far, we have been recommending that people use autocrlf (or .gitattributes) on Windows, which works well enough for the majority of cases.

Your request is reasonable for some workflows though, where LF needs to be used throughout, but this topic is not a priority for us. Your assessment is probably accurate, i.e. you will probably not need to change many more places than the ones you've already mentioned. To add this feature, the setting should be added to SharedConfig, as this is something one might want to configure both globally and on a per-project level (override). So if you want to explore this and issue a PR, feel free to do so.