fix: multi-language support and web search citations (#104)

[bhavyakeerthi3]

🌟 Summary

This PR addresses Issue #104 ("RAG only responds in English") and completes the integration of external web search results. It enables the chatbot to act as a globally accessible research assistant by handling cross-lingual queries with high scientific precision.

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Key Improvement: Multi-Language Support (#104)

The Problem: The agent was hardcoded to English in rephrasing steps and often failed to deliver the final response in the user's native language, even when correctly detected.

The Solution:

• Enforced Target Language: Updated the summarize_reactome_uniprot system prompt to strictly prioritize the {detected_language} for the final response.
• Scientific Precision: Added explicit instructions to preserve exact biological terminology (gene names, pathway IDs) during translation to ensure the expert summary remains accurate.
• Cross-Lingual Strategy: Internal query rephrasing remains in English to maximize vector search accuracy in the primarily English Reactome/UniProt databases, while the final node handles the translation back to the user.

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Key Improvement: Web Search Integration

The Problem: While the graph logic for the Tavily fallback was fixed previously, the search results were not being piped to the final summarizer node.

The Solution:

• Wired Data Flow: Updated generate_final_response in cross_database.py to correctly map and pass web_results to the summarization chain.
• Citations: Updated the summarizer to cite and link external web sources clearly alongside Reactome and UniProt hits, providing a "comprehensive and insightful" fallback experience.

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Files Modified

File	Change
src/agent/tasks/cross_database/summarize_reactome_uniprot.py	Enforced output language & cited web results
src/agent/profiles/cross_database.py	Wired web_results data flow to the final node
src/agent/tasks/rephrase.py	Clarified the "English-for-Search" strategy

Verification

Verified the logic flow of the LangGraph. The agent now successfully handles the lifecycle: Multi-lingual Input → Precision English Search → Multi-DB Research → Native Language Summary with Citations.