feat: Update model references to MiniCPM5 and adjust related documentation and tests for transformers 5.x compatibility

Refactor local model configurations and update tests

feat: Update model routing and local provider to support multi-sponsor tiers and auto-class resolution

feat: Replace llama.cpp backend with in-process transformers backend for local GPU inference

feat: Implement llama.cpp backend for local inference with GGUF models

feat(core): add resilient loop and shared blackboard

feat: Enhance model routing and deployment flexibility

feat: unify model catalogue and self-hosted routing

feat: update model endpoint URLs and enhance documentation with mermaid diagrams

feat: LiteLLM gateway routing profiles to Modal-served small models

Refactor code structure for improved readability and maintainability