logiguard fork v2: patched GPUI on verified 8c74db0 tree

Rebuilt from the exact zed-industries/zed @ 8c74db00c4053d6c0a9037863d7bd048658da4ca
tree (previous orphan was based on a stale/wrong fetch). Same 3-file patch:
  - 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)

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

crates/text/src/subscription.rs

@@ -0,0 +1,67 @@
+use crate::{Edit, Patch};
+use parking_lot::Mutex;
+use std::{
+    mem,
+    sync::{Arc, Weak},
+};
+
+#[derive(Default)]
+pub struct Topic<T>(Mutex<Vec<Weak<Mutex<Patch<T>>>>>);
+
+pub struct Subscription<T>(Arc<Mutex<Patch<T>>>);
+
+impl<T: Default, TDelta> Topic<T>
+where
+    T: 'static
+        + Copy
+        + Ord
+        + std::ops::Sub<T, Output = TDelta>
+        + std::ops::Add<TDelta, Output = T>
+        + std::ops::AddAssign<TDelta>
+        + Default,
+    TDelta: Ord + Copy,
+{
+    pub fn subscribe(&mut self) -> Subscription<T> {
+        let subscription = Subscription(Default::default());
+        self.0.get_mut().push(Arc::downgrade(&subscription.0));
+        subscription
+    }
+
+    pub fn publish(&self, edits: impl Clone + IntoIterator<Item = Edit<T>>) {
+        publish(&mut self.0.lock(), edits);
+    }
+
+    pub fn publish_mut(&mut self, edits: impl Clone + IntoIterator<Item = Edit<T>>) {
+        publish(self.0.get_mut(), edits);
+    }
+}
+
+impl<T: Default> Subscription<T> {
+    pub fn consume(&self) -> Patch<T> {
+        mem::take(&mut *self.0.lock())
+    }
+}
+
+fn publish<T, TDelta>(
+    subscriptions: &mut Vec<Weak<Mutex<Patch<T>>>>,
+    edits: impl Clone + IntoIterator<Item = Edit<T>>,
+) where
+    T: 'static
+        + Copy
+        + Ord
+        + std::ops::Sub<T, Output = TDelta>
+        + std::ops::Add<TDelta, Output = T>
+        + std::ops::AddAssign<TDelta>
+        + Default,
+    TDelta: Ord + Copy,
+{
+    subscriptions.retain(|subscription| {
+        if let Some(subscription) = subscription.upgrade() {
+            let mut patch = subscription.lock();
+            *patch = patch.compose(edits.clone());
+            true
+        } else {
+            false
+        }
+    });
+}