Port · Build: Zed's gpui at 1a28cff

gpui and gpui_platform now come from Zed's repo by git at 1a28cff,
the code gpui-pre 0.3.7 republishes, so the gallery can later build
for the browser. gpui takes stacker, as 0.2.2 always did, and
gpui_platform takes font-kit, without which macOS draws no text;
runtime_shaders moves to gpui_platform.

The API moved: focus, blur and Tab steps take cx, Corner is Anchor,
shaped lines paint with an alignment, defer_draw takes a content
mask, the inspector registers a factory, async updates return their
value, and wrapped lines are shared, not cloned. Updates through a
window context go through the window, so a closed window still ends
them as it did.

Where the new gpui behaves differently, Ely keeps its old intent.
Holds and reveals under a resting pointer survive typing through
gpui's input-modality-independent hover; previews the keyboard also
moves keep the default, and the calendar's leave ignores a key press.
Enter reaches a button inside the code editor, since gpui now arms a
key click on the press. The event logger skips a lone modifier. A
video and an image grid keep their shape in a flex column under
taffy 0.13, as a picture does.

AGENTS.md records the new stack and the rules this port changes; the
rest of the old gpui and taffy rules are re-tested in T44c.

src/collab/tests.rs

@@ -49,7 +49,7 @@ fn open(following: bool, cx: &mut TestAppContext) -> (Entity<Desk>, &mut VisualT
     cx.update(|window, cx| {
         window.activate_window();
         let field = desk.read(cx).field.clone();
-        window.focus(&field.focus_handle(cx));
+        window.focus(&field.focus_handle(cx), cx);
     });
     cx.run_until_parked();
     (desk, cx)
@@ -84,7 +84,7 @@ fn following_begun_from_outside_still_stops_on_escape(cx: &mut TestAppContext) {
     let (desk, cx) = open(false, cx);
     cx.update(|window, cx| {
         let outside = desk.read(cx).outside.focus_handle(cx);
-        window.focus(&outside);
+        window.focus(&outside, cx);
     });
     desk.update(cx, |desk, cx| {
         desk.following = true;