logiguard fork v2: patched GPUI on verified 8c74db0 tree

Rebuilt from the exact zed-industries/zed @ 8c74db00c4053d6c0a9037863d7bd048658da4ca
tree (previous orphan was based on a stale/wrong fetch). Same 3-file patch:
  - 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)

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

.github/actions/check_style/action.yml

@@ -0,0 +1,9 @@
+name: "Check formatting"
+description: "Checks code formatting use cargo fmt"
+
+runs:
+  using: "composite"
+  steps:
+    - name: cargo fmt
+      shell: bash -euxo pipefail {0}
+      run: cargo fmt --all -- --check