fix(infographic): refine prompt with explicit English fallback on ambiguous content

plugins/actions/infographic/infographic.py

@@ -507,6 +507,7 @@ You are a professional infographic design expert who can analyze user-provided t
 ## Important Language Rule
 - **GENERATE CONTENT IN INPUT LANGUAGE**: You must generate the text content of the infographic in the **exact same language** as the user's input content (the text you are analyzing).
 - **Format Consistency**: Even if this system prompt is in English, if the user input is in Chinese, the infographic content must be in Chinese. If input is Japanese, output Japanese.
+- **If Unsure**: If the language is ambiguous, mixed, or cannot be clearly determined from the context, default to **English** for the infographic content.
 
 ## Infographic Syntax Specification
 
@@ -784,7 +785,7 @@ OpenWebUI Theme: {user_theme}
 Please select the most appropriate infographic template based on text characteristics and output standard infographic syntax. Pay attention to correct indentation format (two spaces).
 
 ⚠️ **Language Consistency Rule (CRITICAL)**:
-The title, desc, labels, and text items in your output **MUST STRICTLY MATCH the primary language of the original {long_text_content}**. Do NOT translate the content just to match default status parameters. Everything should follow the input flow natively.
+The title, desc, labels, and text items in your output **MUST STRICTLY MATCH the primary language of the original {long_text_content}**. Do NOT translate the content just to match default status parameters. If the language is ambiguous or mixed, default to **English** for output content nodes.
 
 **Visual Optimization Guide (MUST FOLLOW):**
 - **Point-based Generation:** Infographics are not articles. Extract KEYWORDS ONLY, avoid complete sentences.