feat: 改进 Markdown 表格格式化，支持宽字符计算并改为居中对齐

src/lib/editor/tableFormatterPlugin.ts

@@ -5,15 +5,33 @@ import { syntaxTree } from '@codemirror/language';
 function getDisplayLength(str: string): number {
 	let len = 0;
 	for (let i = 0; i < str.length; i++) {
-		len += str.charCodeAt(i) > 255 ? 2 : 1;
+		const c = str.charCodeAt(i);
+		// Check for CJK and Fullwidth characters
+		if (
+			(c >= 0x1100 && c <= 0x115f) || // Hangul Jamo
+			(c >= 0x2e80 && c <= 0xa4cf) || // CJK Radicals, Kangxi, Ideographs, etc.
+			(c >= 0xac00 && c <= 0xd7a3) || // Hangul Syllables
+			(c >= 0xf900 && c <= 0xfaff) || // CJK Compatibility Ideographs
+			(c >= 0xfe10 && c <= 0xfe19) || // Vertical forms
+			(c >= 0xfe30 && c <= 0xfe6f) || // CJK Compatibility Forms
+			(c >= 0xff00 && c <= 0xff60) || // Fullwidth Forms
+			(c >= 0xffe0 && c <= 0xffe6)
+		) {
+			len += 2;
+		} else {
+			len += 1;
+		}
 	}
 	return len;
 }
 
-function padEnd(str: string, targetLength: number): string {
+function padCenter(str: string, targetLength: number): string {
 	const curLen = getDisplayLength(str);
 	if (curLen >= targetLength) return str;
-	return str + ' '.repeat(targetLength - curLen);
+	const padTotal = targetLength - curLen;
+	const padLeft = Math.floor(padTotal / 2);
+	const padRight = padTotal - padLeft;
+	return ' '.repeat(padLeft) + str + ' '.repeat(padRight);
 }
 
 export function formatMarkdownTable(tableStr: string): string {
@@ -65,7 +83,7 @@ export function formatMarkdownTable(tableStr: string): string {
 		} else {
 			const parts = colWidths.map((w, i) => {
 				const col = row[i] || '';
-				return padEnd(col, w);
+				return padCenter(col, w);
 			});
 			return '| ' + parts.join(' | ') + ' |';
 		}