Refactor Switch Functionality

[somni1oquist]

Currently switch model is a stand-alone endpoint so it needs to be integrated into /papers/search endpoint. And due to the nature of class-level field/method, the flow won't enter the switch process hence the service will still use the default model.

• [ ] Integrate switch endpoint into search endpoint
• [ ] Refactor the GeminiService and change fields/methods to instance-level

[Halffancyy]

Refactor Switch Functionality

[Halffancyy]

Work Done:

• Model Switching: Successfully switched to gemini-1.5-pro during the proceed process, ensuring the correct model is used for searches.
• Logging: Added logs to track model switching between gemini-1.5-pro and gemini-1.5-flash for better visibility.

Remaining Issue:

• Instruction Box: Interaction via the instruction box still defaults to gemini-1.5-flash instead of gemini-1.5-pro.
• Frontend Error: Encountered the error "Did not attempt to load JSON data because the request Content-Type was not 'application/json'." likely due to actions.ts or SearchForm.tsx, which may need further fixes.