M4.54: Placing a text file asks for Text Import Options and sets it as area type

file.place of a .txt file takes `text: {characterSet: unicode|ansi, platform: windows|mac,
removeLineReturns, removeParagraphReturns, replaceSpaces}`: Unicode reads UTF-8 or UTF-16 by its
byte-order mark (other bytes as the platform's 8-bit set), ANSI reads Windows-1252 or Mac Roman;
CR LF, CR and LF all break lines; joining lines makes each block one paragraph, blank lines can
go, and runs of spaces can become tabs. The text becomes area type filling `rect`, the replaced
object's bounds, or the artboard less a 36 pt margin (type reflows rather than scaling), as one
undo step. The place cursor and file.place.info take text files too, and File → Place lists them.

In the app, placing a text file (the Place dialog, a drop, file.place without options) opens the
Text Import Options dialog. Its dropdown rows share a form helper with Document Setup.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/lib.rs

@@ -1031,6 +1031,8 @@ mod tests_targeting;
 #[cfg(test)]
 mod tests_textedit;
 #[cfg(test)]
+mod tests_textimport;
+#[cfg(test)]
 mod tests_tileedge;
 #[cfg(test)]
 mod tests_tints;