Feat: begin sample explorer overhaul

src/views/render.rs

@@ -299,6 +299,13 @@ fn render_side_panel(frame: &mut Frame, app: &App, area: Rect) {
             let [tree_area, preview_area] =
                 Layout::vertical([Constraint::Fill(1), Constraint::Length(6)]).areas(area);
 
+            // Compute visible height: tree_area minus borders (2), minus search bar (1) if shown
+            let mut vh = tree_area.height.saturating_sub(2) as usize;
+            if state.search_active || !state.search_query.is_empty() {
+                vh = vh.saturating_sub(1);
+            }
+            state.visible_height.set(vh);
+
             let entries = state.entries();
             SampleBrowser::new(&entries, state.cursor)
                 .scroll_offset(state.scroll_offset)
@@ -542,6 +549,13 @@ fn render_footer(frame: &mut Frame, app: &App, snapshot: &SequencerSnapshot, are
         ])
     } else {
         let bindings: Vec<(&str, &str)> = match app.page {
+            Page::Main if app.panel.visible && app.panel.focus == PanelFocus::Side => vec![
+                ("↑↓", "Navigate"),
+                ("→", "Expand/Play"),
+                ("←", "Collapse"),
+                ("/", "Search"),
+                ("Tab", "Close"),
+            ],
             Page::Main => vec![
                 ("Space", "Play"),
                 ("Enter", "Edit"),