- Fix f-string quote style (double→single) in _build_filename_error_message
- Remove unused XmlFile import from test file
- Add missing blank lines before DEFAULT_FILE_SYSTEM_PATH
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Allow dots, spaces, and parentheses in filenames (e.g. report.v2.md, my file.csv)
- Auto-sanitize invalid filenames instead of rejecting them (spaces→hyphens, strip bad chars)
- Add specific error messages for binary extensions (.png, .jpg, etc.) to stop infinite retry loops
- Add specific error messages for unsupported extensions explaining which ones are valid
- Add .html and .xml as supported file types
- Improve write_file tool description with explicit filename rules and append behavior
- Add HtmlFile and XmlFile classes
- Add comprehensive tests for sanitization, new file types, and error messages
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>