logiguard fork: GPUI xdg-activation keyboard-focus serial fix

Single-commit orphan branch: full zed-industries/zed @ 8c74db0 source tree
with a 3-file patch applied (no upstream history).

Patch (crates/gpui_linux/src/linux/wayland/):
  - 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)

Mutter honors window activation only when the token carries the keyboard-
focus serial from wl_keyboard.enter; GPUI used a stale mouse-press serial.
See docs/tray-window-focus-wayland.md in logiguard.

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

crates/extension_api/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "zed_extension_api"
+version = "0.8.0"
+description = "APIs for creating Zed extensions in Rust"
+repository = "https://github.com/zed-industries/zed"
+documentation = "https://docs.rs/zed_extension_api"
+keywords = ["zed", "extension"]
+edition.workspace = true
+# Change back to `true` when we're ready to publish v0.8.0.
+publish = false
+license = "Apache-2.0"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/extension_api.rs"
+
+[dependencies]
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+wit-bindgen = "0.41"
+
+[package.metadata.component]
+target = { path = "wit" }