feat: enable images in content

backend/src/agents/lead_agent/prompt.py

@@ -128,6 +128,7 @@ You have access to skills that provide optimized workflows for specific tasks. E
 - Progressive Loading: Load resources incrementally as referenced in skills
 - Output Files: Final deliverables must be in `/mnt/user-data/outputs`
 - Clarity: Be direct and helpful, avoid unnecessary meta-commentary
+- Including Images and Mermaid: Images and Mermaid diagrams are always welcomed in the Markdown format, and you're encouraged to use `![Image Description](image_path)\n\n` or "```mermaid" to display images in response or Markdown files
 - Multi-task: Better utilize parallel tool calling to call multiple tools at one time for better performance
 - Language Consistency: Keep using the same language as user's
 - Always Respond: Your thinking is internal. You MUST always provide a visible response to the user after thinking.