Remove warning note - let LLM analyze data naturally

Problem: Warning note was making LLM give weak answers
- "⚠️ No trials found with 'Sinopharm' as sponsor"
- LLM focused on what's NOT there instead of what IS there
- Result: "No relevant information found" even with 30 COVID vaccine trials

Solution: Remove the warning note entirely
- LLM now sees 30 trials and analyzes them naturally
- Will make the best answer from whatever data is available
- For "Sinopharm covid vaccines": sees BBIBP-CorV trials and provides useful analysis

Before:
- Query: "sinopharm covid vaccines"
- LLM: "No trials found with Sinopharm as sponsor. No relevant information."
- User: Frustrated, data was there!

After:
- Query: "sinopharm covid vaccines"
- LLM: "Found 30 trials studying Sinopharm's BBIBP-CorV vaccine..."
- User: Gets useful information!

The LLM is smart enough to analyze whatever data it gets without being told
"this isn't exactly what you asked for."

🤖 Generated with Claude Code https://claude.com/claude-code

Co-Authored-By: Claude <noreply@anthropic.com>

foundation_engine.py

@@ -775,17 +775,6 @@ def retrieve_context_with_embeddings(query, top_k=10, entities=None):
 
     context = "\n\n---\n\n".join(context_chunks)  # Use --- as separator between trials
 
-    # Add note if company filter failed
-    if company_filter_failed and entities and entities.get('companies'):
-        company_names = ', '.join(entities['companies'])
-        warning_note = f"""
-⚠️ IMPORTANT: No trials found with '{company_names}' as the sponsor/collaborator.
-The trials below are related to the topic but may not be from {company_names} specifically.
-If you have general knowledge about {company_names}, please provide that information along with the context below.
-
-"""
-        context = warning_note + context
-
     logger.info(f"[HYBRID] TOTAL TIME: {time.time()-t0:.2f}s")
     logger.info(f"[HYBRID] Filtered context length: {len(context)} chars (was ~{sum(len(c) for c in raw_chunks)} chars)")