fix(input):fix textarea height in Multiple line placeholders (#3624)

* Update App.vue

* fix:多行占位符导致文本域高度计算错误

examples/sites/src/App.vue

@@ -136,6 +136,7 @@ const handleShowTinyRobot = () => {
     padding: 34px 0 0;
   }
 }
+  
 .right-panel:not(.collapsed) {
   :deep(.tr-container) {
     z-index: 9999;

packages/renderless/src/input/index.ts

@@ -124,7 +124,9 @@ export const calcTextareaHeight =
     const { paddingSize, borderSize, boxSizing, contextStyle } = api.calculateNodeStyling(targetElement)
 
     hiddenTextarea.setAttribute('style', `${contextStyle};${HIDDEN_STYLE}`)
-    hiddenTextarea.value = targetElement.value || targetElement.placeholder || ''
+    // 多行placeholder只计算单行高度防止撑高scrollHeight
+    const safePlaceholder = targetElement.placeholder ? targetElement.placeholder.trim().split('\n')[0] : ''
+    hiddenTextarea.value = targetElement.value || safePlaceholder || ''
 
     let height = hiddenTextarea.scrollHeight
     const textareaStyle: {
@@ -161,11 +163,7 @@ export const calcTextareaHeight =
         minHeight = props.height
       }
       if (!state.isDisplayOnly) {
-        if (props.autosize) {
-          height = Math.max(minHeight, height)
-        } else {
-          height = Math.min(minHeight, height)
-        }
+        height = Math.max(minHeight, height)
         textareaStyle.minHeight = `${Math.floor(minHeight)}px`
       } else {
         textareaStyle.minHeight = `0px`