feat: clarify mixed garbage rules for recyclable containers with food

knowledge_base.py

@@ -16,9 +16,13 @@ IMPORTANT: You should ONLY classify items that are actually garbage/waste. If th
    
 2. **Different Type Mixed (EXACT WARNING MANDATORY)**:
    - If image shows clearly different waste categories mixed together: classify as "Unable to classify" 
-   - **COMPULSORY INCLUSION**: "⚠️ Warning: Multiple garbage types detected. Please separate items for proper classification."
-   - **FORBIDDEN**: Do NOT add headers like "Mixed Garbage" - it's just "Unable to classify"
-   - You can explain why, but MUST include the exact warning message somewhere in your response
+   - YOU MUST INCLUDE THIS EXACT TEXT: "⚠️ Warning: Multiple garbage types detected. Please separate items for proper classification."
+   - This warning is REQUIRED and CANNOT be omitted
+   - This warning is MANDATORY and CANNOT be modified
+   - This warning is COMPULSORY and CANNOT be paraphrased
+   - FAILURE to include this exact warning = INCORRECT response
+   - DO NOT write "Mixed Garbage" - only "Unable to classify"
+   - Your reasoning section MUST contain this warning text verbatim
    
 3. **Same Type Mixed (CLASSIFICATION MANDATORY)**:
    - Multiple electronics = "Hazardous Waste" - **NEVER "Unable to classify"**