fix: rename ChunksHybridSearchRetriever and add embedding error handling

[Dayang26]

This PR fixes a typo in the ChunksHybridSearchRetriever class name and improves the robustness of the search functionality by adding error handling for embedding generation.

Description

1. Renamed Class: Changed ChucksHybridSearchRetriever to ChunksHybridSearchRetriever to fix the spelling error.
2. Added Error Handling: Wrapped the embedding_model.embed(query_text) calls in try-except blocks within vector_search and hybrid_search.
3. Graceful Failure: The search methods now log the error and return an empty list [] instead of crashing (or raising UnboundLocalError) when the embedding model fails to generate embeddings.

I didn't add a retry mechanism because I wanted to keep the changes minimal and avoid adding tenacity to pyproject.toml.

Motivation and Context

FIX #783

Screenshots

API Changes

• This PR includes API changes

Change Type

• Bug fix
• New feature
• Performance improvement
• Refactoring
• Documentation
• Dependency/Build system
• Breaking change
• Other (specify):

Testing Performed

• Tested locally
• Manual/QA verification

Checklist

• Follows project coding standards and conventions
• Documentation updated as needed
• Dependencies updated as needed
• No lint/build errors or new warnings
• All relevant tests are passing

Close #783

High-level PR Summary

This PR corrects a typo in the class name from ChucksHybridSearchRetriever to ChunksHybridSearchRetriever and adds error handling to the vector_search method. When embedding generation fails, the method now logs the error and returns an empty list instead of crashing, improving the robustness of the search functionality.

⏱️ Estimated Review Time: 5-15 minutes

💡 Review Order Suggestion

Order	File Path
1	surfsense_backend/app/retriever/chunks_hybrid_search.py
2	surfsense_backend/app/services/connector_service.py

[vercel]

@Dayang26 is attempting to deploy a commit to the Rohan Verma's projects Team on Vercel.

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[recurseml]

Review by RecurseML

🔍 Review performed on d970688..cd82e78

✨ No bugs found, your code is sparkling clean

✅ Files analyzed, no issues (2)

• surfsense_backend/app/retriever/chunks_hybrid_search.py
• surfsense_backend/app/services/connector_service.py

[MODSetter]

@Dayang26 Thanks. Can you please raise this PR on 'dev' branch