logiguard fork: GPUI xdg-activation keyboard-focus serial fix

Single-commit orphan branch: full zed-industries/zed @ 8c74db0 source tree
with a 3-file patch applied (no upstream history).

Patch (crates/gpui_linux/src/linux/wayland/):
  - serial.rs: add SerialKind::KeyboardEnter
  - client.rs: store wl_keyboard.enter serial; add latest_serial_of()
  - window.rs: activate() uses keyboard-enter serial (Mutter focus gate)

Mutter honors window activation only when the token carries the keyboard-
focus serial from wl_keyboard.enter; GPUI used a stale mouse-press serial.
See docs/tray-window-focus-wayland.md in logiguard.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/gpui/examples/pattern.rs

@@ -0,0 +1,130 @@
+#![cfg_attr(target_family = "wasm", no_main)]
+
+use gpui::{
+    App, AppContext, Bounds, Context, Window, WindowBounds, WindowOptions, div, linear_color_stop,
+    linear_gradient, pattern_slash, prelude::*, px, rgb, size,
+};
+use gpui_platform::application;
+
+struct PatternExample;
+
+impl Render for PatternExample {
+    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
+        div()
+            .flex()
+            .flex_col()
+            .gap_3()
+            .bg(rgb(0xffffff))
+            .size(px(600.0))
+            .justify_center()
+            .items_center()
+            .shadow_lg()
+            .text_xl()
+            .text_color(rgb(0x000000))
+            .child("Pattern Example")
+            .child(
+                div()
+                    .flex()
+                    .flex_col()
+                    .border_1()
+                    .border_color(gpui::blue())
+                    .child(div().w(px(54.0)).h(px(18.0)).bg(pattern_slash(
+                        gpui::red(),
+                        18.0 / 4.0,
+                        18.0 / 4.0,
+                    )))
+                    .child(div().w(px(54.0)).h(px(18.0)).bg(pattern_slash(
+                        gpui::red(),
+                        18.0 / 4.0,
+                        18.0 / 4.0,
+                    )))
+                    .child(div().w(px(54.0)).h(px(18.0)).bg(pattern_slash(
+                        gpui::red(),
+                        18.0 / 4.0,
+                        18.0 / 4.0,
+                    )))
+                    .child(div().w(px(54.0)).h(px(18.0)).bg(pattern_slash(
+                        gpui::red(),
+                        18.0 / 4.0,
+                        18.0 / 2.0,
+                    ))),
+            )
+            .child(
+                div()
+                    .flex()
+                    .flex_col()
+                    .border_1()
+                    .border_color(gpui::blue())
+                    .bg(gpui::green().opacity(0.16))
+                    .child("Elements the same height should align")
+                    .child(div().w(px(256.0)).h(px(56.0)).bg(pattern_slash(
+                        gpui::red(),
+                        56.0 / 6.0,
+                        56.0 / 6.0,
+                    )))
+                    .child(div().w(px(256.0)).h(px(56.0)).bg(pattern_slash(
+                        gpui::green(),
+                        56.0 / 6.0,
+                        56.0 / 6.0,
+                    )))
+                    .child(div().w(px(256.0)).h(px(56.0)).bg(pattern_slash(
+                        gpui::blue(),
+                        56.0 / 6.0,
+                        56.0 / 6.0,
+                    )))
+                    .child(div().w(px(256.0)).h(px(26.0)).bg(pattern_slash(
+                        gpui::yellow(),
+                        56.0 / 6.0,
+                        56.0 / 6.0,
+                    ))),
+            )
+            .child(
+                div()
+                    .border_1()
+                    .border_color(gpui::blue())
+                    .w(px(240.0))
+                    .h(px(40.0))
+                    .bg(gpui::red()),
+            )
+            .child(
+                div()
+                    .border_1()
+                    .border_color(gpui::blue())
+                    .w(px(240.0))
+                    .h(px(40.0))
+                    .bg(linear_gradient(
+                        45.,
+                        linear_color_stop(gpui::red(), 0.),
+                        linear_color_stop(gpui::blue(), 1.),
+                    )),
+            )
+    }
+}
+
+fn run_example() {
+    application().run(|cx: &mut App| {
+        let bounds = Bounds::centered(None, size(px(600.0), px(600.0)), cx);
+        cx.open_window(
+            WindowOptions {
+                window_bounds: Some(WindowBounds::Windowed(bounds)),
+                ..Default::default()
+            },
+            |_window, cx| cx.new(|_cx| PatternExample),
+        )
+        .unwrap();
+
+        cx.activate(true);
+    });
+}
+
+#[cfg(not(target_family = "wasm"))]
+fn main() {
+    run_example();
+}
+
+#[cfg(target_family = "wasm")]
+#[wasm_bindgen::prelude::wasm_bindgen(start)]
+pub fn start() {
+    gpui_platform::web_init();
+    run_example();
+}