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/gpui/examples/ownership_post.rs

@@ -0,0 +1,50 @@
+#![cfg_attr(target_family = "wasm", no_main)]
+
+use gpui::{App, Context, Entity, EventEmitter, prelude::*};
+use gpui_platform::application;
+
+struct Counter {
+    count: usize,
+}
+
+struct Change {
+    increment: usize,
+}
+
+impl EventEmitter<Change> for Counter {}
+
+fn run_example() {
+    application().run(|cx: &mut App| {
+        let counter: Entity<Counter> = cx.new(|_cx| Counter { count: 0 });
+        let subscriber = cx.new(|cx: &mut Context<Counter>| {
+            cx.subscribe(&counter, |subscriber, _emitter, event, _cx| {
+                subscriber.count += event.increment * 2;
+            })
+            .detach();
+
+            Counter {
+                count: counter.read(cx).count * 2,
+            }
+        });
+
+        counter.update(cx, |counter, cx| {
+            counter.count += 2;
+            cx.notify();
+            cx.emit(Change { increment: 2 });
+        });
+
+        assert_eq!(subscriber.read(cx).count, 4);
+    });
+}
+
+#[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();
+}