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>

crates/vim/test_data/test_change_backspace.json

@@ -0,0 +1,16 @@
+{"Put":{"state":"Teˇst"}}
+{"Key":"c"}
+{"Key":"backspace"}
+{"Get":{"state":"Tˇst","mode":"Insert"}}
+{"Put":{"state":"Tˇest"}}
+{"Key":"c"}
+{"Key":"backspace"}
+{"Get":{"state":"ˇest","mode":"Insert"}}
+{"Put":{"state":"ˇTest"}}
+{"Key":"c"}
+{"Key":"backspace"}
+{"Get":{"state":"ˇTest","mode":"Insert"}}
+{"Put":{"state":"Test\nˇtest"}}
+{"Key":"c"}
+{"Key":"backspace"}
+{"Get":{"state":"Testˇtest","mode":"Insert"}}