Type: Character Alignment — where smaller characters line up with a line's largest

Characters of different sizes on one line all sat on the Roman baseline.
Japanese layout usually lines them up by their ideographic em boxes
instead (a 16 pt 第一回 next to 32 pt 雅楽 centred on it, not sitting on
its baseline). The Character panel menu now has Character Alignment:

- `CharStyle.char_align`: Roman Baseline (as before, the default), or the
  em box Top/Right, Center or Bottom/Left: a character smaller than the
  line's largest moves so that its em box top, centre or bottom lines up
  with the largest's (the em box from the font's vertical metrics, else
  0.12 em below the baseline to 0.88 em above it). Vertical type the
  same across the column (top → right). Written only when not Roman
  Baseline.
- `text.setFormat {charAlign: "romanBaseline"|"emBoxTop"|"emBoxCenter"|
  "emBoxBottom"}`; the menu shows the selection's setting; catalog rows
  in ja and zh-hant.
- Not yet: aligning on the ICF (average character face) top and bottom.

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

crates/engine/src/cmd/panelcmds.rs

@@ -24,7 +24,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Character / Paragraph",
             [],
             None,
-            "{ids?|id?, kerning?: 1/1000 em|\"auto\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, underline?, strikethrough?, allCaps?, smallCaps?: bool, position?: \"normal\"|\"superscript\"|\"subscript\" (sizes from Document Setup), leftIndent?, rightIndent?, firstLineIndent?, spaceBefore?, spaceAfter?: pt, hyphenate?: bool, mojikumi?: \"none\"|\"lineEndHalf\" (Japanese punctuation spacing), direction?: \"auto\"|\"leftToRight\"|\"rightToLeft\" (paragraph direction; auto: from each paragraph's first strong character), leadingModel?: \"romanBaseline\"|\"emBoxTop\" (leading measured baseline to baseline, or em box top to top)}",
+            "{ids?|id?, kerning?: 1/1000 em|\"auto\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, underline?, strikethrough?, allCaps?, smallCaps?: bool, position?: \"normal\"|\"superscript\"|\"subscript\" (sizes from Document Setup), leftIndent?, rightIndent?, firstLineIndent?, spaceBefore?, spaceAfter?: pt, hyphenate?: bool, mojikumi?: \"none\"|\"lineEndHalf\" (Japanese punctuation spacing), direction?: \"auto\"|\"leftToRight\"|\"rightToLeft\" (paragraph direction; auto: from each paragraph's first strong character), leadingModel?: \"romanBaseline\"|\"emBoxTop\" (leading measured baseline to baseline, or em box top to top), charAlign?: \"romanBaseline\"|\"emBoxTop\"|\"emBoxCenter\"|\"emBoxBottom\" (where characters smaller than the largest on their line line up with it)}",
             has_doc,
             set_format
         ),
@@ -114,11 +114,22 @@ fn set_format(s: &mut Session, p: &Value) -> Result<Value> {
         "mojikumi",
         "direction",
         "leadingModel",
+        "charAlign",
     ];
     if !keys.iter().any(|k| p.get(*k).is_some()) {
         return Err(bad(C, "nothing to change"));
     }
     let (position, small_caps) = super::docsetup::script_params(p, &s.doc()?.doc.setup, C)?;
+    let char_align = match p.get("charAlign") {
+        None => None,
+        Some(v) => Some(match v.as_str() {
+            Some("romanBaseline") => vectorcraft_doc::CharAlign::RomanBaseline,
+            Some("emBoxTop") => vectorcraft_doc::CharAlign::EmBoxTop,
+            Some("emBoxCenter") => vectorcraft_doc::CharAlign::EmBoxCenter,
+            Some("emBoxBottom") => vectorcraft_doc::CharAlign::EmBoxBottom,
+            _ => return Err(bad(C, "`charAlign` must be \"romanBaseline\", \"emBoxTop\", \"emBoxCenter\" or \"emBoxBottom\"")),
+        }),
+    };
     let mojikumi = match p.get("mojikumi") {
         None => None,
         Some(v) => Some(match v.as_str() {
@@ -179,6 +190,9 @@ fn set_format(s: &mut Session, p: &Value) -> Result<Value> {
                 if let Some(v) = small_caps {
                     st.small_caps = v;
                 }
+                if let Some(v) = char_align {
+                    st.char_align = v;
+                }
             }
             let para = &mut t.para;
             if let Some(v) = num("leftIndent") {

crates/engine/src/cmd/typecmd.rs

@@ -433,6 +433,27 @@ mod area_tests {
         assert!(serde_json::to_value(&text(&s).para).unwrap().get("leading_model").is_none());
     }
 
+    #[test]
+    fn character_alignment_is_a_character_attribute_saved_only_when_set() {
+        use vectorcraft_doc::CharAlign;
+        let mut s = Session::new();
+        s.execute("file.new", &json!({"width": 400, "height": 400})).unwrap();
+        let id = s.execute("text.create", &json!({"x": 10, "y": 50, "text": "雅楽"})).unwrap()["id"].as_u64().unwrap();
+        let runs = |s: &Session| match &s.doc().unwrap().doc.node(NodeId(id)).unwrap().kind {
+            NodeKind::Text(t) => t.runs.clone(),
+            _ => panic!("text"),
+        };
+        assert_eq!(runs(&s)[0].style.char_align, CharAlign::RomanBaseline);
+        assert!(serde_json::to_value(&runs(&s)[0].style).unwrap().get("charAlign").is_none());
+        s.execute("select.set", &json!({"ids": [id]})).unwrap();
+        assert!(s.execute("text.setFormat", &json!({"charAlign": "middle"})).is_err());
+        s.execute("text.setFormat", &json!({"charAlign": "emBoxCenter"})).unwrap();
+        assert!(runs(&s).iter().all(|r| r.style.char_align == CharAlign::EmBoxCenter));
+        assert_eq!(serde_json::to_value(&runs(&s)[0].style).unwrap()["charAlign"], "emBoxCenter");
+        s.execute("edit.undo", &json!({})).unwrap();
+        assert_eq!(runs(&s)[0].style.char_align, CharAlign::RomanBaseline);
+    }
+
     #[test]
     fn new_type_is_composed_with_line_end_half_width_punctuation() {
         use vectorcraft_doc::Mojikumi;