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/markdown_preview/Cargo.toml

@@ -0,0 +1,40 @@
+[package]
+name = "markdown_preview"
+version = "0.1.0"
+edition.workspace = true
+publish.workspace = true
+license = "GPL-3.0-or-later"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/markdown_preview.rs"
+
+[features]
+test-support = []
+
+[dependencies]
+anyhow.workspace = true
+editor.workspace = true
+gpui.workspace = true
+language.workspace = true
+log.workspace = true
+markdown.workspace = true
+project.workspace = true
+settings.workspace = true
+theme.workspace = true
+theme_settings.workspace = true
+ui.workspace = true
+urlencoding.workspace = true
+util.workspace = true
+workspace.workspace = true
+zed_actions.workspace = true
+
+[dev-dependencies]
+editor = { workspace = true, features = ["test-support"] }
+fs.workspace = true
+gpui = { workspace = true, features = ["test-support"] }
+serde_json.workspace = true
+tempfile.workspace = true
+workspace = { workspace = true, features = ["test-support"] }

crates/markdown_preview/LICENSE-GPL

@@ -0,0 +1 @@
+../../LICENSE-GPL

crates/markdown_preview/src/markdown_preview.rs

@@ -0,0 +1,42 @@
+use gpui::{App, actions};
+use workspace::Workspace;
+
+pub mod markdown_preview_view;
+
+pub use zed_actions::preview::markdown::{OpenPreview, OpenPreviewToTheSide};
+
+actions!(
+    markdown,
+    [
+        /// Scrolls up by one page in the markdown preview.
+        #[action(deprecated_aliases = ["markdown::MovePageUp"])]
+        ScrollPageUp,
+        /// Scrolls down by one page in the markdown preview.
+        #[action(deprecated_aliases = ["markdown::MovePageDown"])]
+        ScrollPageDown,
+        /// Scrolls up by approximately one visual line.
+        ScrollUp,
+        /// Scrolls down by approximately one visual line.
+        ScrollDown,
+        /// Scrolls up by one markdown element in the markdown preview
+        ScrollUpByItem,
+        /// Scrolls down by one markdown element in the markdown preview
+        ScrollDownByItem,
+        /// Scrolls to the top of the markdown preview.
+        ScrollToTop,
+        /// Scrolls to the bottom of the markdown preview.
+        ScrollToBottom,
+        /// Opens a following markdown preview that syncs with the editor.
+        OpenFollowingPreview
+    ]
+);
+
+pub fn init(cx: &mut App) {
+    cx.observe_new(|workspace: &mut Workspace, window, cx| {
+        let Some(window) = window else {
+            return;
+        };
+        markdown_preview_view::MarkdownPreviewView::register(workspace, window, cx);
+    })
+    .detach();
+}