M7: area type vertical alignment

Area Type Options > Align: Top / Center / Bottom / Justify (AreaOptions.verticalAlign,
LayoutOptions.vertical_align). Each row/column cell is aligned on its own; rectangular
cells shift their lines, other frames and text wrap reflow until settled without
losing text. Justify shares the leftover space equally between line gaps. Area Type Options
shows Align and First Baseline as dropdowns (the parameter dialog's choices table).

crates/text/src/lib.rs

@@ -31,7 +31,7 @@ use kurbo::{Affine, BezPath, Point, Rect, Vec2};
 pub use layout::{layout, layout_with};
 pub use vectorcraft_doc::TextObject;
 
-pub use vectorcraft_doc::FirstBaseline;
+pub use vectorcraft_doc::{FirstBaseline, VerticalAlign};
 
 /// Paragraph composer; stored per text object in [`vectorcraft_doc::ParaStyle::composer`].
 pub use vectorcraft_doc::Composer;
@@ -50,6 +50,8 @@ pub struct LayoutOptions {
     pub first_baseline: FirstBaseline,
     /// Minimum first-baseline offset in points.
     pub first_baseline_min: f64,
+    /// Vertical alignment of the lines in each row/column (Area Type Options "Align").
+    pub vertical_align: VerticalAlign,
     /// Overrides the object's paragraph composer (`None` = use `ParaStyle::composer`).
     pub composer: Option<Composer>,
     pub features: OtFeatures,
@@ -64,6 +66,7 @@ impl Default for LayoutOptions {
             inset: 0.0,
             first_baseline: FirstBaseline::Ascent,
             first_baseline_min: 0.0,
+            vertical_align: VerticalAlign::Top,
             composer: None,
             features: OtFeatures::default(),
         }
@@ -124,6 +127,8 @@ pub struct LineInfo {
     /// Horizontal span available to the line (frame span minus indents; the content extent for
     /// point type). Used for hit testing across columns.
     pub avail: (f64, f64),
+    /// Area type: index of the frame cell ([`TextLayout::frames`]) the line sits in (0 otherwise).
+    pub region: usize,
 }
 
 #[derive(Clone, Debug, Default)]