fix(core): serialize dumpData to JSON string in writeToDirectory

- JSON.stringify dumpData before passing to generateDumpScriptTag
- Fixes 'html.replace is not a function' error when writing directory reports

Author: quanru

packages/core/src/types.ts

@@ -854,7 +854,7 @@ export class GroupedActionDump implements IGroupedActionDump {
     const { generateDumpScriptTag, generateImageScriptTag } = require('./dump');
     const { getReportTpl } = require('./utils');
 
-    const dumpScript = generateDumpScriptTag(dumpData);
+    const dumpScript = generateDumpScriptTag(JSON.stringify(dumpData));
 
     // Generate image reference scripts (pointing to separate files)
     const imageScripts = screenshots