fix(docs): register the layout evidence pages; test the two gaps the review found (improvise-felo.13)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

context/test-evidence/layout-cost.md

@@ -101,3 +101,25 @@ what `grid_body` builds for the same window, over the whole grid, an interior
 window, the last row and the empty window. Rival (`grid_window` reading column
 `ci + 1`): fails at `window 0..2 x 0..10`. Widths stay the **whole-grid** maximum,
 because the summary is the same walk `grid_body` did; nothing the user sees moves.
+
+### a_frozen_records_snapshot_replaces_the_live_row_index
+
+`view::layout::lookup_cost_tests`. Three records are frozen, two are then cleared,
+and `with_frozen_records` over the snapshot must draw 3 rows (the control: with no
+snapshot it draws 1). A drill held open while another client removes records is the
+production analogue. Rival (deleting `layout.reindex()` after the snapshot swap):
+fails `left: 1, right: 3`; the whole workspace passed it before this test.
+
+### a_drill_snapshot_replaced_alone_rebuilds_the_layout
+
+`ui::app::tests`. `StartDrill` is `ViewOnly`, so a batch of it alone has no `Model`
+effect to mark the layout stale; the drill pointer in `LayoutBasis` is the only
+thing that rebuilds it. The test starts one snapshot, then a second: the first
+step alone passes even with a constant pointer (drill absent to present changes the
+basis), which is why the second step is the test. Rival (pointer replaced by a
+constant): fails `no rebuild for a second drill snapshot`.
+
+### Observation: the TUI frame
+
+`tui_frame_grid_of_whole` is still 47-53 ms at 19,683 rows after this change: the
+draw path projects the whole grid, linear and out of scope for this ticket.

crates/improvise-command/src/ui/app.rs

@@ -1663,6 +1663,32 @@ mod tests {
         app
     }
 
+    /// improvise-felo.13: `StartDrill` is `ViewOnly`, so a batch of it alone moves
+    /// the layout with no `Model` effect to mark it stale. Evidence: layout-cost.md.
+    #[test]
+    fn a_drill_snapshot_replaced_alone_rebuilds_the_layout() {
+        let mut app = records_app_for_drill();
+        assert_eq!(app.layout.row_count(), 3);
+        let rows: Vec<_> = app.layout.records.as_ref().unwrap().to_vec();
+        let start = |app: &mut App, n: usize| {
+            let snapshot = rows.iter().take(n).cloned().collect();
+            app.apply_effects(vec![Box::new(crate::ui::effect::StartDrill(snapshot))]);
+        };
+        start(&mut app, 1);
+        assert_eq!(
+            app.layout.row_count(),
+            1,
+            "the layout draws the frozen snapshot"
+        );
+        let builds = app.layout_builds;
+        start(&mut app, 2);
+        assert!(
+            app.layout_builds > builds,
+            "no rebuild for a second drill snapshot"
+        );
+        assert_eq!(app.layout.row_count(), 2);
+    }
+
     /// The opening basis may be read off `App::layout` only when no drill froze
     /// it. Evidence: `context/test-evidence/command.md`.
     #[test]

crates/improvise-core/src/view/layout.rs

@@ -3133,6 +3133,38 @@ mod lookup_cost_tests {
         }
     }
 
+    /// improvise-felo.13: a drill held open while records are removed elsewhere.
+    /// Evidence: layout-cost.md.
+    #[test]
+    fn a_frozen_records_snapshot_replaces_the_live_row_index() {
+        use crate::model::cell::{CellKey, CellValue};
+        let mut wb = Workbook::new("T");
+        wb.add_category("Region").unwrap();
+        wb.add_item("_Measure", "Revenue").unwrap();
+        let cell = |i: usize| {
+            CellKey::new(vec![
+                ("Region".into(), format!("r{i}")),
+                ("_Measure".into(), "Revenue".into()),
+            ])
+        };
+        for i in 0..3 {
+            wb.add_item("Region", format!("r{i}")).unwrap();
+            wb.model.set_cell(cell(i), CellValue::Number(1.0));
+        }
+        let v = wb.active_view_mut();
+        v.set_axis("_Index", Axis::Row);
+        v.set_axis("_Dim", Axis::Column);
+        let frozen = GridLayout::new(&wb.model, wb.active_view()).records;
+        wb.model.clear_cell(&cell(1));
+        wb.model.clear_cell(&cell(2));
+        let live = GridLayout::with_frozen_records(&wb.model, wb.active_view(), None);
+        assert_eq!(live.row_count(), 1, "the control: one record is live");
+        let held = GridLayout::with_frozen_records(&wb.model, wb.active_view(), frozen);
+        assert_eq!(held.row_count(), 3);
+        assert_eq!(held.row_tuple(2), Some(&["2".to_string()][..]));
+        assert!(held.cell_key(2, 0).is_some());
+    }
+
     fn data_items_entry(items: &[super::AxisEntry], n: usize) -> Option<&super::AxisEntry> {
         items
             .iter()

scripts/build-doc-site.mjs

@@ -81,6 +81,8 @@ const SECTIONS = [
       ["context/test-evidence/cli.md", "test-evidence/cli", "The headless CLI"],
       ["context/test-evidence/gp.md", "test-evidence/gp", "gp-tree and improvise-gp"],
       ["context/test-evidence/tooling.md", "test-evidence/tooling", "The repository's own gates"],
+      ["context/test-evidence/layout-cost.md", "test-evidence/layout-cost", "Layout and keypress cost"],
+      ["context/test-evidence/scale-bisect.md", "test-evidence/scale-bisect", "Scale bisect"],
     ],
   },
   {