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/language_extension/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "language_extension"
+version = "0.1.0"
+edition.workspace = true
+publish.workspace = true
+license = "GPL-3.0-or-later"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/language_extension.rs"
+
+[dependencies]
+anyhow.workspace = true
+async-trait.workspace = true
+collections.workspace = true
+extension.workspace = true
+futures.workspace = true
+fs.workspace = true
+gpui.workspace = true
+language.workspace = true
+log.workspace = true
+lsp.workspace = true
+project.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+tracing.workspace = true
+util.workspace = true
+ztracing.workspace = true
+
+[package.metadata.cargo-machete]
+ignored = ["tracing"]