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

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

refactor: update artifact URLs and improve router device handling for better classification performance

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

docs: reorganize documentation structure and workflow