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/extension_api/wit/since_v0.4.0/process.wit

@@ -0,0 +1,29 @@
+interface process {
+    use common.{env-vars};
+
+    /// A command.
+    record command {
+        /// The command to execute.
+        command: string,
+        /// The arguments to pass to the command.
+        args: list<string>,
+        /// The environment variables to set for the command.
+        env: env-vars,
+    }
+
+    /// The output of a finished process.
+    record output {
+        /// The status (exit code) of the process.
+        ///
+        /// On Unix, this will be `None` if the process was terminated by a signal.
+        status: option<s32>,
+        /// The data that the process wrote to stdout.
+        stdout: list<u8>,
+        /// The data that the process wrote to stderr.
+        stderr: list<u8>,
+    }
+
+    /// Executes the given command as a child process, waiting for it to finish
+    /// and collecting all of its output.
+    run-command: func(command: command) -> result<output, string>;
+}