IDML export: write the document's default StoryPreference

InDesign always writes a document-level StoryPreference in
Resources/Preferences.xml; DesignCraft only wrote one per story. IDML readers
that take the spread reading order from the document's preference, such as
Okapi's IDML filter, failed on DesignCraft's files without it.

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

ROADMAP.md

@@ -380,6 +380,7 @@ list) · [roadmap.md](docs/roadmap.md) (milestones, plan) · [parity-checklist.m
 
 Newest first.
 
+- **2026-10-28** · IDML export writes the document's default `StoryPreference` in `Resources/Preferences.xml`, as InDesign does. Only each story carried one, and IDML readers that take the spread reading order from the document's (Okapi's IDML filter) failed on DesignCraft's files. No readiness percentage change.
 - **2026-10-27** · An iconic panel's flyout stays open while you work in the canvas or a text field: Auto-Collapse Iconic Panels is off by default, and preferences saved with it on start with it off. Preferences › Interface › Panels holds the setting next to the column bar's menu item. No readiness percentage change.
 - **2026-10-24** · Column rules run from the top line's ascent to the bottom line's descent, as InDesign draws them, instead of from the top to the bottom of the columns, on screen, in PDF and in PowerPoint export. The top and bottom insets shorten the rule from those lines. Existing documents draw their column rules at the new length. No readiness percentage change.
 - **2026-10-20** · Edit › Keyboard Shortcuts is craft-keymap's shared dialog: commands grouped by menu with Show and Filter, recording that asks before taking a key from another command, undo and redo, named shortcut sets (edits of Default become Custom; an imported set becomes a set of its own), an on-screen US keyboard, InDesign Show Set files reviewed before they apply, JSON export and an HTML summary. ui.json keeps the `shortcuts` map earlier versions read, for the active set. No readiness percentage change.

crates/idml/src/export/fonts_prefs.rs

@@ -169,6 +169,16 @@ impl<'a> Ex<'a> {
                 .attr("SubscriptSize", num(a.subscript_size))
                 .attr("SubscriptPosition", num(a.subscript_position)),
         );
+        // InDesign always writes the document's default story preference; readers such as Okapi's IDML
+        // filter take the spread reading order from it and fail without it.
+        root.push(
+            El::new("StoryPreference")
+                .attr("OpticalMarginAlignment", "false")
+                .attr("OpticalMarginSize", "12")
+                .attr("FrameType", "TextFrameType")
+                .attr("StoryOrientation", "Horizontal")
+                .attr("StoryDirection", "LeftToRightDirection"),
+        );
         document(&root)
     }
 }

crates/idml/src/tests.rs

@@ -554,6 +554,14 @@ fn basic_paragraph_is_normal_paragraph_style() {
     assert_eq!(back.styles.paragraph.iter().filter(|p| p.name == st::BASIC_PARAGRAPH).count(), 1);
 }
 
+/// Like InDesign, the export carries the document's default story preference, which IDML readers expect.
+#[test]
+fn export_writes_the_document_story_preference() {
+    let d = import_idml_with(&fixture(), &|_| None).unwrap();
+    let prefs = zip_text(&export_idml(&d), "Resources/Preferences.xml");
+    assert!(prefs.contains(r#"<StoryPreference OpticalMarginAlignment="false" OpticalMarginSize="12" FrameType="TextFrameType" StoryOrientation="Horizontal" StoryDirection="LeftToRightDirection"/>"#), "{prefs}");
+}
+
 /// Page items, frames, tables and preferences an IDML file leaves unset are InDesign's defaults
 /// for a new document.
 #[test]