Fix: Pet clinic chatbot agent fabrication issues

[github-actions]

Summary

Fixes critical issues identified in the pet clinic chatbot system to prevent AI hallucination and improve error handling without adding new pet types.

Changes Made

Agent Configuration ✅

• Updated nutrition agent prompts - Strict guidelines to prevent product fabrication
• Implemented "information not available" fallback responses - Graceful handling when data is missing
• Added validation before product recommendations - Only recommend products that exist in database
• Enhanced error handling - Better service unavailability messaging
• Improved primary agent - Prevents fabrication and provides proper fallbacks

Technical Improvements

• Enhanced get_nutrition_data() function with proper error states
• Added validation in create_order() to prevent fake product orders
• Updated system prompts with strict anti-fabrication guidelines
• Improved error messaging to direct users to veterinary consultation

Impact

• Eliminates AI hallucination - No more fake product recommendations like "AvianVital"
• Improves customer experience - Clear messaging when information unavailable
• Maintains service reliability - Graceful degradation when services are down
• Prevents fabrication - Agents only recommend existing products

Testing Recommendations

• Test nutrition queries for existing pet types (cat, dog, bird, hamster, lizard, snake)
• Verify error handling when nutrition service is unavailable
• Confirm agents no longer fabricate non-existent products
• Test order placement with valid vs invalid product names

Note: This PR does NOT add new pet type data - it only improves agent behavior and error handling for existing supported pets.

Fixes the critical issues identified in the Application Signals investigation.

[liustve]

LGTM!!