feat(app): 增强文字元素渲染 — 多行+字号+颜色

app/lib/features/editor/widgets/draggable_element.dart

@@ -146,16 +146,25 @@ class _DraggableElementState extends State<DraggableElement> {
 
     switch (element.elementType) {
       case ElementType.text:
+        final text = element.content['text'] as String? ?? '';
+        final fontSize = (element.content['fontSize'] as num?)?.toDouble() ?? 18.0;
+        final fontColor = element.content['fontColor'] as String? ?? '#2D2420';
+        final color = _parseColor(fontColor);
         return Container(
-          color: Colors.white,
-          padding: const EdgeInsets.all(8),
-          alignment: Alignment.centerLeft,
+          padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+          decoration: BoxDecoration(
+            color: Colors.white.withValues(alpha: 0.9),
+            borderRadius: BorderRadius.circular(4),
+          ),
           child: Text(
-            element.content['text'] as String? ?? '',
+            text,
             style: TextStyle(
-              fontSize: (element.content['fontSize'] as num?)?.toDouble() ?? 16,
-              color: _parseColor(element.content['fontColor'] as String?),
+              fontSize: fontSize,
+              color: color,
+              fontFamily: 'NotoSansSC',
             ),
+            maxLines: null,
+            softWrap: true,
           ),
         );