fix: transformer toc prompt text incorrect (#12116)

### What problem does this PR solve?

Fix incorrect prompt texts in **Agent** canvas > **Transformer** >
**Result destination: Table of contents**

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/locales/en.ts

@@ -1789,6 +1789,7 @@ This delimiter is used to split the input text into several text pieces echo of
       variableSettings: 'Variable settings',
       systemPrompt: 'System prompt',
       userPrompt: 'User prompt',
+      tocDataSource: 'Data source',
       addCategory: 'Add category',
       categoryName: 'Category name',
       nextStep: 'Next step',
@@ -2024,6 +2025,7 @@ Key Instructions:
           metadata: `Extract important structured information from the given content. Output ONLY a valid JSON string with no additional text. If no important structured information is found, output an empty JSON object: {}.
 
 Important structured information may include: names, dates, locations, events, key facts, numerical data, or other extractable entities.`,
+          toc: '',
         },
         user: {
           keywords: `Text Content
@@ -2033,6 +2035,7 @@ Important structured information may include: names, dates, locations, events, k
           summary: `Text to Summarize:
 [Insert text here]`,
           metadata: `Content: [INSERT CONTENT HERE]`,
+          toc: '[Insert text here]',
         },
       },
       cancel: 'Cancel',