fix(prompt-input): leave a composition-ending Escape to the IME

src/hooks/use-prompt-input.test.ts

@@ -293,11 +293,38 @@ describe("usePromptInput", () => {
     const view = mountPrompt();
     try {
       view.type("@a");
-      view.press("Escape", { isComposing: true });
+      expect(view.press("Escape", { isComposing: true, keyCode: 27 })).toBe(
+        true,
+      );
+      expect(seen).toEqual([]);
+      expect(view.prompt.activeSuggestion?.id).toBe("ada");
       view.press("Escape");
       expect(view.prompt.suggestions).toEqual([]);
       view.press("Escape");
-      expect(seen).toEqual([false, true, false]);
+      expect(seen).toEqual([true, false]);
+    } finally {
+      view.unmount();
+      document.removeEventListener("keydown", layer, { capture: true });
+    }
+  });
+
+  test("Safari's composition-ending Escape (keyCode 229) is left to the IME", () => {
+    const seen: boolean[] = [];
+    const layer = (event: KeyboardEvent) => {
+      if (event.key === "Escape") seen.push(event.defaultPrevented);
+    };
+    document.addEventListener("keydown", layer, { capture: true });
+    const view = mountPrompt();
+    try {
+      view.type("@a");
+      expect(view.press("Escape", { isComposing: false, keyCode: 229 })).toBe(
+        true,
+      );
+      expect(seen).toEqual([]);
+      expect(view.prompt.activeSuggestion?.id).toBe("ada");
+      view.press("Escape");
+      expect(view.prompt.suggestions).toEqual([]);
+      expect(seen).toEqual([true]);
     } finally {
       view.unmount();
       document.removeEventListener("keydown", layer, { capture: true });

src/hooks/use-prompt-input.ts

@@ -153,21 +153,23 @@ export function usePromptInput({
   // A Radix dialog or popover around the prompt dismisses on an Escape it
   // sees in the document's capture phase, before React's handlers run,
   // unless the event is already marked handled. While the list is open, mark
-  // it first from the window's capture phase; `onKeyDown` still closes the
-  // list, so propagation is left alone.
+  // a normal Escape from the window's capture phase and let it propagate so
+  // `onKeyDown` can close the list. Stop a composing Escape instead, without
+  // preventDefault, so the dialog never sees it.
   useEffect(() => {
     const element = textareaRef.current;
     if (!listOpen || element === null) return;
     const view = element.ownerDocument.defaultView;
     if (view === null) return;
     const claimEscape = (event: KeyboardEvent) => {
-      if (
-        event.key === "Escape" &&
-        event.target === element &&
-        !event.isComposing
-      ) {
-        event.preventDefault();
+      if (event.key !== "Escape" || event.target !== element) return;
+      // 229 is what Safari reports for the key that ends a composition,
+      // after `isComposing` has already turned false.
+      if (event.isComposing || event.keyCode === 229) {
+        event.stopPropagation();
+        return;
       }
+      event.preventDefault();
     };
     view.addEventListener("keydown", claimEscape, { capture: true });
     return () =>