The command palette stays where it's scrolled (#658)

The command palette follows its selection only when the arrow keys or typing move it, so the wheel's scroll isn't pulled back to the top on the next frame (fixes #584).

crates/ui-egui/src/palette.rs

@@ -101,6 +101,9 @@ pub fn show(app: &mut CraftApp, ctx: &egui::Context) {
         p.selected = p.selected.saturating_sub(1);
     }
     p.selected = p.selected.min(n.saturating_sub(1));
+    // The list follows the selection only when the keys or typing moved it: every frame would pull
+    // the wheel's scroll back to it (#584).
+    let mut follow = down || up;
     let mut chosen: Option<usize> = None;
     let screen = ctx.content_rect();
     let width = 620.0_f32.min(screen.width() - 40.0);
@@ -128,6 +131,7 @@ pub fn show(app: &mut CraftApp, ctx: &egui::Context) {
                     r.request_focus();
                     if r.changed() {
                         app.state.palette.selected = 0;
+                        follow = true;
                     }
                 });
                 ui.add_space(6.0);
@@ -142,7 +146,7 @@ pub fn show(app: &mut CraftApp, ctx: &egui::Context) {
                         if on || r.hovered() {
                             ui.painter().rect_filled(rect, t.radius_sm, if on { t.accent_soft } else { t.hover });
                         }
-                        if on {
+                        if on && follow {
                             r.scroll_to_me(None);
                         }
                         let (icon, title, sub, tag) = match e {

crates/ui-egui/tests/smoke.rs

@@ -960,6 +960,33 @@ fn command_palette_opens_and_lists_tools() {
     assert!(!h.state().state.palette.open);
 }
 
+/// #584: the palette's list jumped back to the top after every scroll, because the selected row
+/// asked to be scrolled into view on every frame.
+#[test]
+fn the_command_palette_stays_where_it_was_scrolled() {
+    let mut h = harness(|| demo::app(demo::engine(Mode::Experienced, true)));
+    h.run_steps(3);
+    h.key_press_modifiers(egui::Modifiers::COMMAND, egui::Key::K);
+    h.run_steps(3);
+    let before = h.get_by_label("Session status").rect();
+    // Over the list's first rows (this one may be below what the list shows).
+    h.event(egui::Event::PointerMoved(egui::pos2(before.center().x, 250.0)));
+    h.event(egui::Event::MouseWheel {
+        unit: egui::MouseWheelUnit::Point,
+        delta: egui::vec2(0.0, -300.0),
+        phase: egui::TouchPhase::Move,
+        modifiers: egui::Modifiers::NONE,
+    });
+    h.run_steps(20);
+    let after = h.get_by_label("Session status").rect();
+    assert!(after.top() < before.top() - 100.0, "it scrolled and stayed scrolled: {before:?} → {after:?}");
+    // The arrow keys still bring the selection back into view.
+    h.key_press(egui::Key::ArrowDown);
+    h.key_press(egui::Key::ArrowUp);
+    h.run_steps(20);
+    assert_eq!(h.get_by_label("Session status").rect().top(), before.top());
+}
+
 /// A stand-in model server whose every answer lists an embedding model, then `qwen3:8b`. Its
 /// OpenAI-style address.
 fn model_server() -> String {

docs/ROADMAP.md

@@ -501,6 +501,8 @@ Gaps found while using the app for real projects.
       check against DNS rebinding), streams large files instead of reading them into memory,
       sends no body for HEAD on a missing file, and caps open connections and the time a
       request may take to arrive (#597, #598, #600, #601, by Afloat16)
+- [x] The command palette stays where the wheel scrolls it; it follows the selection only when the
+      arrow keys or typing move it (#584)
 
 ### R2.10 Pinned builds
 Owner: maintainers · Status: in progress

docs/pitfalls.md

@@ -564,3 +564,8 @@ parser between JSON recovery and ReAct: count the opener, require a standalone c
 least that long, and reject an earlier matching close followed by more text. Shorter backtick
 lines inside a longer fence are content. Test both paths and the next HTTP request, including
 malformed suffixes and non-call JSON examples whose strings contain protocol markers.
+
+**A view that asked to be scrolled on every frame.** The command palette called `scroll_to_me` on
+the selected row each frame, so the wheel's scroll was pulled back to it at once and the list
+kept jumping to the top (#584). Scroll something into view on the frame it changed (a key, a new
+query), never as a standing request.