Add thinking config with LOW mode and temperature to Gemini API

[trett]

Summary

• Add thinkingConfig with LOW mode to all Gemini API requests for optimized performance
• Add temperature parameter (1.5) to fun fact generation for more creative and varied responses
• Refactor buildGeminiRequest to use circe Json API for type-safe JSON construction

Changes

• buildGeminiRequest method: Enhanced to accept optional temperature parameter and always include thinkingConfig with LOW mode
• generateFunFact method: Now passes temperature = 1.5 for more creative fun facts
• summarize method: Uses default behavior (LOW thinking mode without temperature adjustment) for consistent summaries

Technical Details

• Thinking Config: Uses LOW mode to reduce thinking tokens and improve response speed, suitable for summarization tasks
• Temperature: Set to 1.5 for fun facts to increase creativity while staying reasonable (range 0.0-2.0)
• Type Safety: Refactored to use circe's Json API instead of heterogeneous Maps for proper serialization

Test plan

• Code compiles successfully
• Code formatted with scalafmtAll
• Manual testing of summary generation
• Manual testing of fun fact generation with varied responses

🤖 Generated with Claude Code