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/breadcrumbs/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "breadcrumbs"
+version = "0.1.0"
+edition.workspace = true
+publish.workspace = true
+license = "GPL-3.0-or-later"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/breadcrumbs.rs"
+doctest = false
+
+[dependencies]
+gpui.workspace = true
+ui.workspace = true
+workspace.workspace = true
+
+[dev-dependencies]
+gpui = { workspace = true, features = ["test-support"] }
+workspace = { workspace = true, features = ["test-support"] }

crates/breadcrumbs/LICENSE-GPL

@@ -0,0 +1 @@
+../../LICENSE-GPL

crates/breadcrumbs/src/breadcrumbs.rs

@@ -0,0 +1,127 @@
+use gpui::{
+    AnyElement, App, Context, EventEmitter, Font, Global, IntoElement, Render, Subscription, Window,
+};
+use ui::prelude::*;
+use workspace::{
+    ToolbarItemEvent, ToolbarItemLocation, ToolbarItemView,
+    item::{HighlightedText, ItemEvent, ItemHandle},
+};
+
+type RenderBreadcrumbTextFn = fn(
+    Vec<HighlightedText>,
+    Option<Font>,
+    Option<AnyElement>,
+    &dyn ItemHandle,
+    bool,
+    &mut Window,
+    &App,
+) -> AnyElement;
+
+pub struct RenderBreadcrumbText(pub RenderBreadcrumbTextFn);
+
+impl Global for RenderBreadcrumbText {}
+
+pub struct Breadcrumbs {
+    pane_focused: bool,
+    active_item: Option<Box<dyn ItemHandle>>,
+    subscription: Option<Subscription>,
+}
+
+impl Default for Breadcrumbs {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Breadcrumbs {
+    pub fn new() -> Self {
+        Self {
+            pane_focused: false,
+            active_item: Default::default(),
+            subscription: Default::default(),
+        }
+    }
+}
+
+impl EventEmitter<ToolbarItemEvent> for Breadcrumbs {}
+
+impl Render for Breadcrumbs {
+    fn render(&mut self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let element = h_flex()
+            .id("breadcrumb-container")
+            .flex_grow()
+            .h_8()
+            .overflow_x_scroll()
+            .text_ui(cx);
+
+        let Some(active_item) = self.active_item.as_ref() else {
+            return element.into_any_element();
+        };
+
+        let Some((segments, breadcrumb_font)) = active_item.breadcrumbs(cx) else {
+            return element.into_any_element();
+        };
+
+        let prefix_element = active_item.breadcrumb_prefix(window, cx);
+
+        if let Some(render_fn) = cx.try_global::<RenderBreadcrumbText>() {
+            (render_fn.0)(
+                segments,
+                breadcrumb_font,
+                prefix_element,
+                active_item.as_ref(),
+                false,
+                window,
+                cx,
+            )
+        } else {
+            element.into_any_element()
+        }
+    }
+}
+
+impl ToolbarItemView for Breadcrumbs {
+    fn set_active_pane_item(
+        &mut self,
+        active_pane_item: Option<&dyn ItemHandle>,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) -> ToolbarItemLocation {
+        cx.notify();
+        self.active_item = None;
+
+        let Some(item) = active_pane_item else {
+            return ToolbarItemLocation::Hidden;
+        };
+
+        let this = cx.entity().downgrade();
+        self.subscription = Some(item.subscribe_to_item_events(
+            window,
+            cx,
+            Box::new(move |event, _, cx| {
+                if let ItemEvent::UpdateBreadcrumbs = event {
+                    this.update(cx, |this, cx| {
+                        cx.notify();
+                        if let Some(active_item) = this.active_item.as_ref() {
+                            cx.emit(ToolbarItemEvent::ChangeLocation(
+                                active_item.breadcrumb_location(cx),
+                            ))
+                        }
+                    })
+                    .ok();
+                }
+            }),
+        ));
+        self.active_item = Some(item.boxed_clone());
+        item.breadcrumb_location(cx)
+    }
+
+    fn pane_focus_update(
+        &mut self,
+        pane_focused: bool,
+        _window: &mut Window,
+        _: &mut Context<Self>,
+    ) {
+        self.pane_focused = pane_focused;
+    }
+}