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>

docs/src/update.md

@@ -0,0 +1,26 @@
+---
+title: Update Zed
+description: "Zed is designed to keep itself up to date automatically. You can always update this behavior in your settings."
+---
+
+# Update Zed
+
+Zed is designed to keep itself up to date automatically. You can always update this behavior in your settings.
+
+## Auto-updates
+
+By default, Zed checks for updates and installs them automatically the next time you restart the app. You’ll always be running the latest version with no extra steps.
+
+If an update is available, Zed will download it in the background and apply it on restart.
+
+## How to check your current version
+
+To check which version of Zed you're using:
+
+Open the Command Palette (Cmd+Shift+P on macOS, Ctrl+Shift+P on Linux/Windows).
+
+Type and select {#action zed::About}. A modal will appear with your version information.
+
+## How to control update behavior
+
+If you want to turn off auto-updates, open the Settings Editor (Cmd ,) and find `Auto Update` under General Settings.