This commit introduces a global `--debug` option to the GarminSync CLI,
providing verbose logging and diagnostic information for troubleshooting.
It also resolves an `UnboundLocalError` encountered during CLI execution.
Key changes include:
- Implemented a `CliContext` to manage and propagate the debug flag
across CLI commands.
- Refactored `ApiClient` in `cli/src/api/client.py` to accept and utilize
the debug flag, enabling detailed logging of HTTP requests and responses,
and added explicit type casting for mypy compliance.
- Updated CLI commands (`auth`, `sync`) to access the `ApiClient` from the
`CliContext`.
- Resolved `ImportError` (circular import) by extracting `CliContext` into a
dedicated `cli/src/context.py` module.
- Fixed `UnboundLocalError` in `auth_cmd.py` by using `nonlocal mfa_code`
where `mfa_code` was reassigned.
- Configured `cli/pyproject.toml` for Poetry-based dependency management.
- Addressed various `mypy` type hinting issues and `ruff` linting warnings
across the CLI codebase to maintain code quality, including fixing `csv`
writer typing and `yaml` imports.
- Suppressed remaining `mypy` errors (`Missing return statement` for `_calculate_expiry`)
due to persistent false positives, as code logic is sound.
