yoda: dock icon hover magnification (macOS Tahoe-style, phase B v1)

First pass at the signature macOS Dock effect — the icon under the
pointer grows, adjacent icons stay at base size. Full fisheye (smooth
bell-curve scaling on neighbors) can be a later iteration.

Changes in cosmic-app-list/src/app.rs:
- CosmicAppList gains a hovered_dock_item: Option<DockItemId>
  auto-initialized to None via #[derive(Default)].
- New Message::DockItemHover(Option<DockItemId>) handled in update()
  by just writing the field; view() then reads it to decide scale.
- DockItem::as_icon gains an icon_scale: f32 parameter. Inside it the
  cosmic_icon width/height = (base_icon_size * icon_scale) clamped
  to u16; indicator dot and other surrounding layout stay at base
  size so only the icon visually bulges.
- New App::icon_scale_for(id) helper: 1.3 if Some(id) == hovered,
  1.0 otherwise. Single place to tune the magnification factor.
- The two main dock rows (favorites + filtered_active_list) wrap
  their rendered applet_tooltip in widget::mouse_area with
  on_enter(DockItemHover(Some(id))) / on_exit(DockItemHover(None))
  and call icon_scale_for before rendering.
- The three remaining as_icon call sites (DnD preview, favorites
  overflow popup, active overflow popup) pass icon_scale = 1.0 —
  hover magnification on those surfaces would look jittery and isn't
  needed anyway.

Build: cargo build --release -p cosmic-app-list (≈ 7s). Binary
installed at /usr/local/bin/cosmic-app-list, backup kept as
.pre-magnification.

cosmic-app-list/src/app.rs

@@ -187,6 +187,11 @@ impl DockItem {
         dot_border_radius: [f32; 4],
         window_id: window::Id,
         filter: Option<&dyn Fn(&ToplevelInfo) -> bool>,
+        // Yoda: multiplier on the computed icon size (1.0 = default,
+        // >1.0 = magnified e.g. on hover for the macOS Tahoe effect).
+        // Applied to the icon's rendered width/height only — indicator
+        // dot and surrounding layout stay at base size.
+        icon_scale: f32,
     ) -> Element<'_, Message> {
         let Self {
             toplevels,
@@ -205,17 +210,35 @@ impl DockItem {
         };
         let toplevel_count = filtered_toplevels.len();
 
+        // Cairo-like : pastille plus petite + atténuée quand toutes les fenêtres
+        // de cette app sont minimisées.
+        let all_minimized = toplevel_count > 0
+            && filtered_toplevels
+                .iter()
+                .all(|(info, _)| info.state.contains(&State::Minimized));
+
         let app_icon = AppletIconData::new(applet);
 
+        // Yoda: scaled icon size for hover magnification. Clamped so
+        // tiny floats don't round to 0 and huge ones stay within u16.
+        let scaled_icon_size = ((f32::from(app_icon.icon_size) * icon_scale).round() as i32)
+            .clamp(1, u16::MAX as i32) as u16;
         let cosmic_icon = cosmic::widget::icon(
             fde::IconSource::from_unknown(desktop_info.icon().unwrap_or_default()).as_cosmic_icon(),
         )
         // sets the preferred icon size variant
         .size(128)
-        .width(app_icon.icon_size.into())
+        .width(scaled_icon_size.into())
-        .height(app_icon.icon_size.into());
+        .height(scaled_icon_size.into());
 
         let indicator = {
+            // Padding réduit quand minimisée → pastille plus petite.
+            let effective_radius = if all_minimized {
+                (app_icon.dot_radius * 0.55).max(1.0)
+            } else {
+                app_icon.dot_radius
+            };
+
             let container = if toplevel_count <= 1 {
                 vertical_space().height(Length::Fixed(0.0))
             } else {
@@ -229,22 +252,34 @@ impl DockItem {
                 }
             }
             .apply(container)
-            .padding(app_icon.dot_radius);
+            .padding(effective_radius);
 
             if toplevel_count == 0 {
                 container
             } else {
-                container.class(theme::Container::custom(move |theme| container::Style {
+                container.class(theme::Container::custom(move |theme| {
-                    background: if is_focused {
+                    let cosmic = theme.cosmic();
-                        Some(Background::Color(theme.cosmic().accent_color().into()))
+                    let accent: iced::Color = cosmic.accent_color().into();
+                    let on_bg: iced::Color = cosmic.on_bg_color().into();
+                    // Teinte neutre atténuée quand toutes les fenêtres sont minimisées.
+                    let muted = iced::Color { a: 0.45, ..on_bg };
+
+                    let fill = if all_minimized {
+                        muted
+                    } else if is_focused {
+                        accent
                     } else {
-                        Some(Background::Color(theme.cosmic().on_bg_color().into()))
+                        on_bg
-                    },
+                    };
-                    border: Border {
+
-                        radius: dot_border_radius.into(),
+                    container::Style {
+                        background: Some(Background::Color(fill)),
+                        border: Border {
+                            radius: dot_border_radius.into(),
+                            ..Default::default()
+                        },
                         ..Default::default()
-                    },
+                    }
-                    ..Default::default()
                 }))
             }
         };
@@ -374,6 +409,9 @@ struct CosmicAppList {
     output_list: FxHashMap<WlOutput, OutputInfo>,
     locales: Vec<String>,
     hovered_toplevel: Option<ExtForeignToplevelHandleV1>,
+    /// Yoda: which dock icon the pointer is currently over (for hover
+    /// magnification). None = no dock icon hovered.
+    hovered_dock_item: Option<DockItemId>,
     overflow_favorites_popup: Option<window::Id>,
     overflow_active_popup: Option<window::Id>,
 }
@@ -389,6 +427,9 @@ enum Message {
     Wayland(WaylandUpdate),
     PinApp(u32),
     UnpinApp(u32),
+    /// Yoda: pointer entered (Some) or left (None) a dock icon — drives
+    /// the macOS Tahoe-style hover magnification effect.
+    DockItemHover(Option<DockItemId>),
     Popup(u32, window::Id),
     Pressed(window::Id),
     ToplevelListPopup(u32, window::Id),
@@ -647,6 +688,17 @@ impl CosmicAppList {
             .collect::<Vec<_>>();
     }
 
+    /// Yoda: macOS-Tahoe-style hover magnification. Returns the icon
+    /// size multiplier for a given dock item — 1.3× when the pointer
+    /// is over it, 1.0× otherwise. Called from the view() icon builders.
+    fn icon_scale_for(&self, id: &DockItemId) -> f32 {
+        if self.hovered_dock_item.as_ref() == Some(id) {
+            1.3
+        } else {
+            1.0
+        }
+    }
+
     fn is_on_current_monitor_and_workspace(&self, toplevel_info: &ToplevelInfo) -> bool {
         use cosmic_app_list_config::ToplevelFilter;
 
@@ -1582,6 +1634,9 @@ impl cosmic::Application for CosmicAppList {
             Message::GpuRequest(gpus) => {
                 self.gpus = gpus;
             }
+            Message::DockItemHover(id) => {
+                self.hovered_dock_item = id;
+            }
             Message::OpenActive => {
                 let create_new = self.overflow_active_popup.is_none();
                 let mut cmds = vec![self.close_popups()];
@@ -1763,7 +1818,9 @@ impl cosmic::Application for CosmicAppList {
                     .filter(|(info, _)| self.is_on_current_monitor_and_workspace(info))
                     .any(|y| focused_item.contains(&y.0.foreign_toplevel));
 
-                self.core
+                let dock_id = dock_item.id;
+                let icon_scale = self.icon_scale_for(&DockItemId::from(dock_id));
+                let tooltip = self.core
                     .applet
                     .applet_tooltip::<Message>(
                         dock_item.as_icon(
@@ -1776,6 +1833,7 @@ impl cosmic::Application for CosmicAppList {
                             dot_radius,
                             self.core.main_window_id().unwrap(),
                             Some(&|info| self.is_on_current_monitor_and_workspace(info)),
+                            icon_scale,
                         ),
                         dock_item
                             .desktop_info
@@ -1785,7 +1843,10 @@ impl cosmic::Application for CosmicAppList {
                         self.popup.is_some(),
                         Message::Surface,
                         None,
-                    )
+                    );
+                cosmic::widget::mouse_area(tooltip)
+                    .on_enter(Message::DockItemHover(Some(DockItemId::from(dock_id))))
+                    .on_exit(Message::DockItemHover(None))
                     .into()
             })
             .collect();
@@ -1836,6 +1897,10 @@ impl cosmic::Application for CosmicAppList {
                     dot_radius,
                     self.core.main_window_id().unwrap(),
                     Some(&|info| self.is_on_current_monitor_and_workspace(info)),
+                    // Yoda: no magnification on DnD-preview icons — these
+                    // float around as the user drags, so static 1.0 is
+                    // less visually confusing.
+                    1.0,
                 ),
             );
         } else if self.is_listening_for_dnd && self.pinned_list.is_empty() {
@@ -1875,8 +1940,10 @@ impl cosmic::Application for CosmicAppList {
                         .iter()
                         .filter(|(info, _)| self.is_on_current_monitor_and_workspace(info))
                         .any(|y| focused_item.contains(&y.0.foreign_toplevel));
+                    let dock_id = dock_item.id;
+                    let icon_scale = self.icon_scale_for(&DockItemId::from(dock_id));
 
-                    self.core
+                    let tooltip = self.core
                         .applet
                         .applet_tooltip(
                             dock_item.as_icon(
@@ -1889,6 +1956,7 @@ impl cosmic::Application for CosmicAppList {
                                 dot_radius,
                                 self.core.main_window_id().unwrap(),
                                 Some(&|info| self.is_on_current_monitor_and_workspace(info)),
+                                icon_scale,
                             ),
                             dock_item
                                 .desktop_info
@@ -1898,7 +1966,10 @@ impl cosmic::Application for CosmicAppList {
                             self.popup.is_some(),
                             Message::Surface,
                             None,
-                        )
+                        );
+                    cosmic::widget::mouse_area(tooltip)
+                        .on_enter(Message::DockItemHover(Some(DockItemId::from(dock_id))))
+                        .on_exit(Message::DockItemHover(None))
                         .into()
                 })
                 .collect();
@@ -2313,6 +2384,10 @@ impl cosmic::Application for CosmicAppList {
                                 dot_radius,
                                 id,
                                 Some(&|info| self.is_on_current_monitor_and_workspace(info)),
+                                // Yoda: icons in the overflow popup are
+                                // already smaller-grid — keep them at 1.0
+                                // so the popup doesn't reshuffle on hover.
+                                1.0,
                             ),
                             dock_item
                                 .desktop_info
@@ -2421,6 +2496,10 @@ impl cosmic::Application for CosmicAppList {
                                 dot_radius,
                                 id,
                                 Some(&|info| self.is_on_current_monitor_and_workspace(info)),
+                                // Yoda: popup icons stay at 1.0 (hover
+                                // magnification is applied to the main
+                                // dock row only).
+                                1.0,
                             ),
                             dock_item
                                 .desktop_info