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

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

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

docs: remove archived planning documents

docs: reorganize documentation structure and workflow