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>

extensions/test-extension/extension.toml

@@ -0,0 +1,25 @@
+id = "test-extension"
+name = "Test Extension"
+description = "An extension for use in tests."
+version = "0.1.0"
+schema_version = 1
+authors = ["Marshall Bowers <elliott.codes@gmail.com>"]
+repository = "https://github.com/zed-industries/zed"
+
+[language_servers.gleam]
+name = "Gleam LSP"
+language = "Gleam"
+
+[grammars.gleam]
+repository = "https://github.com/gleam-lang/tree-sitter-gleam"
+commit = "8432ffe32ccd360534837256747beb5b1c82fca1"
+
+[[capabilities]]
+kind = "process:exec"
+command = "echo"
+args = ["hello from a child process!"]
+
+[[capabilities]]
+kind = "process:exec"
+command = "cmd"
+args = ["/C", "echo", "hello from a child process!"]