refactor: streamline evidence generation in coach summary; enhance JSON output contract and improve tokenization handling for local chat

refactor: add functions for JSON payload extraction and validation in coach summary; streamline summary key handling and improve error reporting

refactor: introduce compact representation functions for metrics, issues, and knowledge cards; enhance summary evidence generation and improve error handling in JSON extraction

refactor: enhance JSON response handling in coach summary generation; update response format instructions and improve error reporting for invalid JSON outputs

chore: remove Linux-specific dependencies from pyproject.toml and requirements.txt; update README to clarify usage of Nemotron implementation for local model inference

chore: add ninja-build and build-essential to package requirements; update README and documentation to reflect changes in model configuration and local Transformers usage

chore: update base model to NVIDIA-Nemotron-3-Nano-4B-BF16 across configurations and documentation; adjust max sequence length to 2048; upgrade GitHub Actions cache to v5

feat: add support for local Transformers inference on Hugging Face Spaces with opt-in configuration

docs: update default coach-summary model to build-small-hackathon/pozify-coach-summary1 and clarify fallback behavior in documentation

feat: add coach summary LoRA config and provider plumbing

feat: expand coach retrieval with equipment and goal overlays

feat(slm): add llama.cpp coach summary provider

feat(coach): add local transformers provider

Implement grounded coach summary with HF SLM