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/tests/text_import_fuzz.rs

@@ -0,0 +1,42 @@
+//! Untrusted text files placed with File → Place never crash: any bytes, with any Text Import
+//! Options, place as area type or fail with an error.
+//!
+//! `PROPTEST_CASES=20000 cargo test -p vectorcraft-engine --test text_import_fuzz` runs a deeper search.
+// Integration tests: unwrapping and panicking on failure is fine here, unlike in shipped code (AGENTS.md › Robustness).
+#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
+
+use proptest::prelude::*;
+use serde_json::json;
+use vectorcraft_testkit::catch_quiet;
+
+proptest! {
+    #![proptest_config(ProptestConfig { cases: 64, failure_persistence: None, ..ProptestConfig::default() })]
+
+    #[test]
+    fn any_bytes_place_as_text_without_panics(
+        bytes in prop::collection::vec(prop_oneof![any::<u8>(), Just(b'\r'), Just(b'\n'), Just(b' ')], 0..400),
+        bom in prop::sample::select(vec![&b""[..], b"\xEF\xBB\xBF", b"\xFF\xFE", b"\xFE\xFF"]),
+        ansi in any::<bool>(),
+        mac in any::<bool>(),
+        lines in any::<bool>(),
+        paras in any::<bool>(),
+        spaces in prop::option::of(0u64..8),
+    ) {
+        let data = [bom, &bytes[..]].concat();
+        let r = catch_quiet(|| {
+            let mut s = vectorcraft_engine::Session::new();
+            s.execute("file.new", &json!({"width": 100, "height": 100})).unwrap();
+            let text = json!({
+                "characterSet": if ansi { "ansi" } else { "unicode" },
+                "platform": if mac { "mac" } else { "windows" },
+                "removeLineReturns": lines,
+                "removeParagraphReturns": paras,
+                "replaceSpaces": spaces,
+            });
+            let p = json!({"name": "fuzz.txt", "dataBase64": vectorcraft_format::base64_encode(&data), "text": text, "thumbnail": 8});
+            let _ = s.execute("file.place.info", &p);
+            let _ = s.execute("file.place", &p);
+        });
+        prop_assert!(r.is_ok(), "panicked: {:?}", r.err());
+    }
+}