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/tests/action_macros.rs

@@ -0,0 +1,55 @@
+use gpui::{Action, actions};
+use gpui_macros::register_action;
+use schemars::JsonSchema;
+use serde::Deserialize;
+
+#[test]
+fn test_action_macros() {
+    actions!(
+        test_only,
+        [
+            SomeAction,
+            /// Documented action
+            SomeActionWithDocs,
+        ]
+    );
+
+    #[derive(PartialEq, Clone, Deserialize, JsonSchema, Action)]
+    #[action(namespace = test_only)]
+    #[serde(deny_unknown_fields)]
+    struct AnotherAction;
+
+    #[derive(PartialEq, Clone, gpui::private::serde::Deserialize)]
+    #[serde(deny_unknown_fields)]
+    struct RegisterableAction {}
+
+    register_action!(RegisterableAction);
+
+    impl gpui::Action for RegisterableAction {
+        fn boxed_clone(&self) -> Box<dyn gpui::Action> {
+            unimplemented!()
+        }
+
+        fn partial_eq(&self, _action: &dyn gpui::Action) -> bool {
+            unimplemented!()
+        }
+
+        fn name(&self) -> &'static str {
+            unimplemented!()
+        }
+
+        fn name_for_type() -> &'static str
+        where
+            Self: Sized,
+        {
+            unimplemented!()
+        }
+
+        fn build(_value: serde_json::Value) -> anyhow::Result<Box<dyn gpui::Action>>
+        where
+            Self: Sized,
+        {
+            unimplemented!()
+        }
+    }
+}