logiguard fork v3: full patch set on verified 8c74db0 tree

Includes prior-session patches (carry forward so the app compiles):
  - crates/gpui/build.rs: cross-compile manifest fix
  - crates/gpui/src/platform.rs: PlatformWindow::activate_with_token trait method
  - crates/gpui/src/window.rs: Window::activate_with_token public API
  - crates/gpui_linux/src/linux/wayland/window.rs: WaylandWindow::activate_with_token + activate() keyboard-serial fix

Plus the focus-serial fix:
  - serial.rs: SerialKind::KeyboardEnter
  - client.rs: store wl_keyboard.enter serial; latest_serial_of()

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/zlog/README.md

@@ -0,0 +1,15 @@
+# Zlog
+
+Use the `ZED_LOG` environment variable to control logging output for Zed
+applications and libraries. The variable accepts a comma-separated list of
+directives that specify logging levels for different modules (crates). The
+general format is for instance:
+
+```
+ZED_LOG=info,project=debug,agent=off
+```
+
+- Levels can be one of: `off`/`none`, `error`, `warn`, `info`, `debug`, or
+  `trace`.
+- You don't need to specify the global level, default is `trace` in the crate
+  and `info` set by `RUST_LOG` in Zed.