Add end_of_line = lf to .editorconfig

The IDE0055 formatting errors were caused by dotnet format defaulting
to CRLF line endings on Windows, while all source files use LF. Adding
an explicit end_of_line = lf setting aligns the formatter with the
actual file line endings and resolves all 26 build errors.

.editorconfig

@@ -2,6 +2,7 @@ root = true
 
 [*]
 charset = utf-8
+end_of_line = lf
 indent_size = 2
 indent_style = space
 insert_final_newline = true