Put the gesture reference in the application

The document the previous commit generates is for somebody reading the
repository. The person who needs it most is holding a tablet, has just
discovered that a hold does something, and has nowhere to ask what else
does.

So the same scan writes a table the application draws: a "Gestures"
button beside Settings, a sheet with the same scrim and dismissal as the
ones that file and name, and every gesture grouped by where it applies
with its touch, pointer and keyboard routes side by side. Not the `why` —
that is the argument for the design and belongs in the document; on a
phone-sized card it would bury the one line the sheet was opened to read.

The sheet's file knows nothing about what a gesture is. It draws the rows
it is handed, and the rows come from the generated table, because a help
screen with its text typed into it is a second description of one
behaviour — and the second description is always the one that goes stale.
The commit before this deleted a gesture; a hand-kept sheet would still
be describing it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ui/dr-ui/src/library_ui.rs

@@ -22,7 +22,7 @@ use dr_types::FormatFilter;
 use slint::{ComponentHandle, Model as _};
 
 use crate::library::{self, ScanMessage, ThumbnailMessage};
-use crate::{AppWindow, KeywordRow, LibraryCell, PersonChip, TimelineBar};
+use crate::{AppWindow, GestureRow, KeywordRow, LibraryCell, PersonChip, TimelineBar};
 
 /// A screenful before the grid has reported its geometry.
 ///
@@ -4512,6 +4512,24 @@ pub fn wire<F>(
     // after it, which is the whole point of showing them.
     window.set_library_touched(cfg!(target_os = "android"));
 
+    // TRACES: FR-UI-4
+    // The gesture reference. Pushed once, here, rather than on demand: the
+    // table is a compiled-in constant, so there is nothing to be fresh about
+    // and nothing to recompute — a callback to fill it would only be a way for
+    // it to be empty the first time the sheet opens.
+    window.set_library_gestures(slint::ModelRc::new(slint::VecModel::from(
+        crate::gestures::rows()
+            .into_iter()
+            .map(|r| GestureRow {
+                heading: r.heading.into(),
+                title: r.title.into(),
+                touch: r.touch.into(),
+                pointer: r.pointer.into(),
+                keys: r.keys.into(),
+            })
+            .collect::<Vec<_>>(),
+    )));
+
     // Shared rather than moved: a click and `Return` both open an image, and
     // they are two callbacks.
     let on_open_image = Rc::new(on_open_image);