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_tokio/src/gpui_tokio.rs

@@ -0,0 +1,100 @@
+use std::future::Future;
+
+use gpui::{App, AppContext, Global, ReadGlobal, Task};
+use util::defer;
+
+pub use tokio::task::JoinError;
+
+/// Initializes the Tokio wrapper using a new Tokio runtime with 2 worker threads.
+///
+/// If you need more threads (or access to the runtime outside of GPUI), you can create the runtime
+/// yourself and pass a Handle to `init_from_handle`.
+pub fn init(cx: &mut App) {
+    let runtime = tokio::runtime::Builder::new_multi_thread()
+        // Since we now have two executors, let's try to keep our footprint small
+        .worker_threads(2)
+        .enable_all()
+        .build()
+        .expect("Failed to initialize Tokio");
+
+    let handle = runtime.handle().clone();
+    cx.set_global(GlobalTokio {
+        owned_runtime: Some(runtime),
+        handle,
+    });
+}
+
+/// Initializes the Tokio wrapper using a Tokio runtime handle.
+pub fn init_from_handle(cx: &mut App, handle: tokio::runtime::Handle) {
+    cx.set_global(GlobalTokio {
+        owned_runtime: None,
+        handle,
+    });
+}
+
+struct GlobalTokio {
+    owned_runtime: Option<tokio::runtime::Runtime>,
+    handle: tokio::runtime::Handle,
+}
+
+impl Global for GlobalTokio {}
+
+impl Drop for GlobalTokio {
+    fn drop(&mut self) {
+        if let Some(runtime) = self.owned_runtime.take() {
+            runtime.shutdown_background();
+        }
+    }
+}
+
+pub struct Tokio {}
+
+impl Tokio {
+    /// Spawns the given future on Tokio's thread pool, and returns it via a GPUI task
+    /// Note that the Tokio task will be cancelled if the GPUI task is dropped
+    pub fn spawn<C, Fut, R>(cx: &C, f: Fut) -> Task<Result<R, JoinError>>
+    where
+        C: AppContext,
+        Fut: Future<Output = R> + Send + 'static,
+        R: Send + 'static,
+    {
+        cx.read_global(|tokio: &GlobalTokio, cx| {
+            let join_handle = tokio.handle.spawn(f);
+            let abort_handle = join_handle.abort_handle();
+            let cancel = defer(move || {
+                abort_handle.abort();
+            });
+            cx.background_spawn(async move {
+                let result = join_handle.await;
+                drop(cancel);
+                result
+            })
+        })
+    }
+
+    /// Spawns the given future on Tokio's thread pool, and returns it via a GPUI task
+    /// Note that the Tokio task will be cancelled if the GPUI task is dropped
+    pub fn spawn_result<C, Fut, R>(cx: &C, f: Fut) -> Task<anyhow::Result<R>>
+    where
+        C: AppContext,
+        Fut: Future<Output = anyhow::Result<R>> + Send + 'static,
+        R: Send + 'static,
+    {
+        cx.read_global(|tokio: &GlobalTokio, cx| {
+            let join_handle = tokio.handle.spawn(f);
+            let abort_handle = join_handle.abort_handle();
+            let cancel = defer(move || {
+                abort_handle.abort();
+            });
+            cx.background_spawn(async move {
+                let result = join_handle.await?;
+                drop(cancel);
+                result
+            })
+        })
+    }
+
+    pub fn handle(cx: &App) -> tokio::runtime::Handle {
+        GlobalTokio::global(cx).handle.clone()
+    }
+}