breadhelp 0.2.0: live guided tour overlay replacing static onboarding

Replaces the old in-window onboarding wizard with a real screen-wide
tour: dim + spotlight cutout around the actual on-screen component
(breadbar, breadbox), floating callout teaching the shortcut, and
event-driven confirmation via real Hyprland/breadd signals instead of
click-through fakery.

src/ui/tour/mask.rs

@@ -0,0 +1,92 @@
+//! The spotlight: up to 4 `Layer::Overlay` strip windows (top/bottom/left/
+//! right) sized to leave a target's bounding box as a real gap with no
+//! surface over it at all — gtk4-layer-shell has no click-through/input-
+//! region API (confirmed in its own docs), so the only way to let pointer
+//! input reach the real UI underneath is to literally not cover it with
+//! anything. A `Target::None` step instead gets one full-screen dim window,
+//! since there's nothing to leave a gap around.
+
+use gtk4::prelude::*;
+use gtk4::{Box as GBox, Window};
+use gtk4_layer_shell::{Edge, KeyboardMode, Layer, LayerShell};
+
+use super::target::Rect;
+
+fn new_mask_window(monitor: &gdk4::Monitor) -> Window {
+    let window = Window::new();
+    window.set_decorated(false);
+    window.add_css_class("tour-window");
+    window.init_layer_shell();
+    window.set_layer(Layer::Overlay);
+    window.set_keyboard_mode(KeyboardMode::None);
+    window.set_monitor(Some(monitor));
+    let dim = GBox::new(gtk4::Orientation::Vertical, 0);
+    dim.add_css_class("tour-mask");
+    dim.set_hexpand(true);
+    dim.set_vexpand(true);
+    window.set_child(Some(&dim));
+    window
+}
+
+/// One dim window covering the whole monitor — used for `Target::None` steps.
+pub fn full_screen(monitor: &gdk4::Monitor) -> Vec<Window> {
+    let window = new_mask_window(monitor);
+    for edge in [Edge::Top, Edge::Bottom, Edge::Left, Edge::Right] {
+        window.set_anchor(edge, true);
+    }
+    window.present();
+    vec![window]
+}
+
+/// The 4-strip letterbox around `rect`, in monitor-local coordinates.
+/// `monitor_size` is `(width, height)` from `gdk4::Monitor::geometry()`.
+pub fn around(monitor: &gdk4::Monitor, rect: Rect, monitor_size: (i32, i32)) -> Vec<Window> {
+    let (mon_w, mon_h) = monitor_size;
+    let mut windows = Vec::new();
+
+    let top_h = rect.y;
+    if top_h > 0 {
+        let w = new_mask_window(monitor);
+        w.set_anchor(Edge::Top, true);
+        w.set_anchor(Edge::Left, true);
+        w.set_anchor(Edge::Right, true);
+        w.set_default_size(-1, top_h);
+        w.present();
+        windows.push(w);
+    }
+
+    let bottom_h = mon_h - (rect.y + rect.h);
+    if bottom_h > 0 {
+        let w = new_mask_window(monitor);
+        w.set_anchor(Edge::Bottom, true);
+        w.set_anchor(Edge::Left, true);
+        w.set_anchor(Edge::Right, true);
+        w.set_default_size(-1, bottom_h);
+        w.present();
+        windows.push(w);
+    }
+
+    let left_w = rect.x;
+    if left_w > 0 {
+        let w = new_mask_window(monitor);
+        w.set_anchor(Edge::Left, true);
+        w.set_anchor(Edge::Top, true);
+        w.set_margin(Edge::Top, rect.y);
+        w.set_default_size(left_w, rect.h);
+        w.present();
+        windows.push(w);
+    }
+
+    let right_w = mon_w - (rect.x + rect.w);
+    if right_w > 0 {
+        let w = new_mask_window(monitor);
+        w.set_anchor(Edge::Right, true);
+        w.set_anchor(Edge::Top, true);
+        w.set_margin(Edge::Top, rect.y);
+        w.set_default_size(right_w, rect.h);
+        w.present();
+        windows.push(w);
+    }
+
+    windows
+}