Learn a photograph's shape from its header

A panorama the merge did not make, a stitch from another program or a
phone's sweep, never had a width or height in the catalog, so it could
never be given a wide cell. The header read that dates a photograph now
records its size as it is seen, orientation applied, alongside the date.

ui/dr-ui/src/library/sweep.rs

@@ -28,6 +28,23 @@ pub struct MetadataFound {
     pub camera: Option<String>,
     pub lens: Option<String>,
     pub iso: Option<u32>,
+    /// TRACES: FR-MRG-6
+    /// Width and height as the photograph is seen — orientation applied —
+    /// where the header says: what gives a panorama from elsewhere, a
+    /// stitch from another program or a phone's sweep, its wide cell.
+    pub size: Option<(u32, u32)>,
+}
+
+impl MetadataFound {
+    /// The upright size a header describes.
+    pub fn upright_size(md: &dr_decode::Metadata) -> Option<(u32, u32)> {
+        let (w, h) = (md.width?, md.height?);
+        if w == 0 || h == 0 {
+            return None;
+        }
+        let turned = md.orientation.is_some_and(|o| o.quarter_turns % 2 == 1);
+        Some(if turned { (h, w) } else { (w, h) })
+    }
 }
 
 /// Write a batch of dates and tell the UI, draining `found`.
@@ -140,7 +157,9 @@ pub fn write_metadata(
                     camera          = coalesce(?4, camera),
                     lens            = coalesce(?5, lens),
                     iso             = coalesce(?6, iso),
-                    metadata_state  = max(metadata_state, ?7)
+                    metadata_state  = max(metadata_state, ?7),
+                    w               = coalesce(?8, w),
+                    h               = coalesce(?9, h)
               WHERE id = ?1",
             rusqlite::params![
                 m.image_id,
@@ -150,6 +169,8 @@ pub fn write_metadata(
                 m.lens,
                 m.iso,
                 state,
+                m.size.map(|s| s.0),
+                m.size.map(|s| s.1),
             ],
         )?;
         if state == 2 {
@@ -404,6 +425,7 @@ pub fn spawn_sweep(conn: Connection, catalog_path: PathBuf) -> Receiver<SweepMes
                             camera: None,
                             lens: None,
                             iso: None,
+                            size: None,
                         }),
                 );
 
@@ -874,6 +896,20 @@ pub(super) fn thumbnails_outstanding(
 mod tests {
     use super::*;
 
+    #[test]
+    fn a_header_gives_the_size_the_photograph_is_seen_at() {
+        let mut md = dr_decode::Metadata {
+            width: Some(9000),
+            height: Some(3000),
+            ..Default::default()
+        };
+        assert_eq!(MetadataFound::upright_size(&md), Some((9000, 3000)));
+        md.orientation = Some(dr_types::Orientation::from_exif(6));
+        assert_eq!(MetadataFound::upright_size(&md), Some((3000, 9000)));
+        md.width = None;
+        assert_eq!(MetadataFound::upright_size(&md), None);
+    }
+
     #[test]
     fn join_all_preserves_order_regardless_of_completion() {
         // The ordering guarantee is what lets a caller pair results back to