- Replace `stats.utils.extractor` with dedicated `loader` and
`converter`
modules to improve code organization.
- Implement explicit pipeline stages for ingestion, decoding, and
precomputation with caching.
- Standardize data loading and J1939 parsing logic across sub-modules.
- Enhance dashboard responsiveness by pre-calculating figures and
downsampling ID-grouped data.
- Enforce strict typing and add docstrings to public components.
eeeck