v2026.07.25.2

Summary of core changes:

• Refactored the core parser architecture to use a dependency-free List[dict] intermediate representation.
• Added first-class support for Polars DataFrames via the as_pl=True parameter and the optional [polars] install directive.
• Implemented runtime dependency guards, allowing pandas and [xarray] to be safely uninstalled for lightweight environments.
• Updated test suites with schema-contract assertions to ensure resilience against upstream data variations.
• Updated documentation and the [overview.ipynb] notebook to demonstrate Polars capabilities and lightweight environment configurations.

Bugfixes:

• None noted.

Future improvements:

• Evaluating a v1 release in which xarray, pandas, and polars are installed as optional using ndbc-api[xarray], ndbc-api[pandas], and ndbc-api[polars] respectively.