Fix PHP serialization and add Long Text type to Visual Editor

- Fixed PHP serialization byte length calculation for escaped strings
- Added Long Text type with textarea for multiline strings in StructuredEditor
- Auto-detects strings with newlines and displays them as textarea
- Improvements apply to both SerializeTool and JsonTool visual editors
- Resolves parse errors with quoted strings and multiline content

src/pages/SerializeTool.js

@@ -21,7 +21,11 @@ const SerializeTool = () => {
       return Number.isInteger(data) ? `i:${data};` : `d:${data};`;
     }
     if (typeof data === 'string') {
-      return `s:${data.length}:"${data}";`;
+      // Escape quotes and backslashes in the string first
+      const escapedData = data.replace(/\\/g, '\\\\').replace(/"/g, '\\"');
+      // PHP serialize requires UTF-8 byte length of the ESCAPED string
+      const byteLength = new TextEncoder().encode(escapedData).length;
+      return `s:${byteLength}:"${escapedData}";`;
     }
     if (Array.isArray(data)) {
       let result = `a:${data.length}:{`;