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/nc/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "nc"
+version = "0.1.0"
+edition.workspace = true
+publish.workspace = true
+license = "GPL-3.0-or-later"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/nc.rs"
+doctest = false
+
+[dependencies]
+anyhow.workspace = true
+futures.workspace = true
+net.workspace = true
+smol.workspace = true

crates/nc/LICENSE-GPL

@@ -0,0 +1 @@
+../../LICENSE-GPL

crates/nc/src/nc.rs

@@ -0,0 +1,51 @@
+use anyhow::Result;
+
+#[cfg(windows)]
+pub fn main(_socket: &str) -> Result<()> {
+    // It looks like we can't get an async stdio stream on Windows from smol.
+    panic!("--nc isn't yet supported on Windows");
+}
+
+/// The main function for when Zed is running in netcat mode
+#[cfg(not(windows))]
+pub fn main(socket: &str) -> Result<()> {
+    use futures::{AsyncReadExt as _, AsyncWriteExt as _, FutureExt as _, io::BufReader, select};
+    use net::async_net::UnixStream;
+    use smol::{Unblock, io::AsyncBufReadExt};
+
+    smol::block_on(async {
+        let socket_stream = UnixStream::connect(socket).await?;
+        let (socket_read, mut socket_write) = socket_stream.split();
+        let mut socket_reader = BufReader::new(socket_read);
+
+        let mut stdout = Unblock::new(std::io::stdout());
+        let stdin = Unblock::new(std::io::stdin());
+        let mut stdin_reader = BufReader::new(stdin);
+
+        let mut socket_line = Vec::new();
+        let mut stdin_line = Vec::new();
+
+        loop {
+            select! {
+                bytes_read = socket_reader.read_until(b'\n', &mut socket_line).fuse() => {
+                    if bytes_read? == 0 {
+                        break
+                    }
+                    stdout.write_all(&socket_line).await?;
+                    stdout.flush().await?;
+                    socket_line.clear();
+                }
+                bytes_read = stdin_reader.read_until(b'\n', &mut stdin_line).fuse() => {
+                    if bytes_read? == 0 {
+                        break
+                    }
+                    socket_write.write_all(&stdin_line).await?;
+                    socket_write.flush().await?;
+                    stdin_line.clear();
+                }
+            }
+        }
+
+        anyhow::Ok(())
+    })
+}