fix: improve editor auto-scroll and Safari IME handling (#5469)

- Use `textarea-caret` for precise cursor position calculation instead of line approximation
- Update `scrollToCursor` to scroll to the actual cursor position
- Fix Safari double-enter issue with IME in list completion

web/src/components/MemoEditor/Editor/index.tsx

 import { forwardRef, useCallback, useEffect, useImperativeHandle, useMemo, useRef } from "react";
+import getCaretCoordinates from "textarea-caret";
 import { cn } from "@/lib/utils";
 import { EDITOR_HEIGHT } from "../constants";
 import type { EditorProps } from "../types";
@@ -74,9 +75,12 @@ const Editor = forwardRef(function Editor(props: EditorProps, ref: React.Forward
       getEditor: () => editorRef.current,
       focus: () => editorRef.current?.focus(),
       scrollToCursor: () => {
-        if (editorRef.current) {
-          editorRef.current.scrollTop = editorRef.current.scrollHeight;
-        }
+        const editor = editorRef.current;
+        if (!editor) return;
+
+        const caret = getCaretCoordinates(editor, editor.selectionEnd);
+        // Scroll to center cursor vertically
+        editor.scrollTop = Math.max(0, caret.top - editor.clientHeight / 2);
       },
       insertText: (content = "", prefix = "", suffix = "") => {
         const editor = editorRef.current;
@@ -148,6 +152,19 @@ const Editor = forwardRef(function Editor(props: EditorProps, ref: React.Forward
     if (editorRef.current) {
       handleContentChangeCallback(editorRef.current.value);
       updateEditorHeight();
+
+      // Auto-scroll to keep cursor visible when typing
+      // See: https://github.com/usememos/memos/issues/5469
+      const editor = editorRef.current;
+      const caret = getCaretCoordinates(editor, editor.selectionEnd);
+      const lineHeight = parseFloat(getComputedStyle(editor).lineHeight) || 24;
+
+      // Scroll if cursor is near or beyond bottom edge (within 2 lines)
+      const viewportBottom = editor.scrollTop + editor.clientHeight;
+      if (caret.top + lineHeight * 2 > viewportBottom) {
+        // Scroll to center cursor vertically
+        editor.scrollTop = Math.max(0, caret.top - editor.clientHeight / 2);
+      }
     }
   }, [handleContentChangeCallback, updateEditorHeight]);
 

web/src/components/MemoEditor/Editor/useListCompletion.ts

@@ -24,15 +24,30 @@ export function useListCompletion({ editorRef, editorActions, isInIME }: UseList
   const editorActionsRef = useRef(editorActions);
   editorActionsRef.current = editorActions;
 
+  // Track when composition ends to handle Safari race condition
+  // Safari fires keydown(Enter) immediately after compositionend, while Chrome doesn't
+  // See: https://github.com/usememos/memos/issues/5469
+  const lastCompositionEndRef = useRef(0);
+
   useEffect(() => {
     const editor = editorRef.current;
     if (!editor) return;
 
+    const handleCompositionEnd = () => {
+      lastCompositionEndRef.current = Date.now();
+    };
+
     const handleKeyDown = (event: KeyboardEvent) => {
       if (event.key !== "Enter" || isInIMERef.current || event.shiftKey || event.ctrlKey || event.metaKey || event.altKey) {
         return;
       }
 
+      // Safari fix: Ignore Enter key within 100ms of composition end
+      // This prevents double-enter behavior when confirming IME input in lists
+      if (Date.now() - lastCompositionEndRef.current < 100) {
+        return;
+      }
+
       const actions = editorActionsRef.current;
       const cursorPosition = actions.getCursorPosition();
       const contentBeforeCursor = actions.getContent().substring(0, cursorPosition);
@@ -51,10 +66,17 @@ export function useListCompletion({ editorRef, editorActions, isInIME }: UseList
       } else {
         const continuation = generateListContinuation(listInfo);
         actions.insertText("\n" + continuation);
+
+        // Auto-scroll to keep cursor visible after inserting list item
+        setTimeout(() => actions.scrollToCursor(), 0);
       }
     };
 
+    editor.addEventListener("compositionend", handleCompositionEnd);
     editor.addEventListener("keydown", handleKeyDown);
-    return () => editor.removeEventListener("keydown", handleKeyDown);
+    return () => {
+      editor.removeEventListener("compositionend", handleCompositionEnd);
+      editor.removeEventListener("keydown", handleKeyDown);
+    };
   }, []);
 }