Harden tests, improve documentation, and optimize accessors - #97

- Refactor `.values` calls in `grid.py` to maintain Dask laziness for mask handling.
- Implement `Regridder.clear_cache()` and `clear_instance_cache()` for improved memory management.
- Add `__del__` to `Regridder` to ensure automatic cleanup of worker-local caches.
- Improve ESMF error handling by translating cryptic codes into descriptive messages.
- Harden `_apply_weights_core` to handle empty or NaN-only input arrays gracefully.
- Add comprehensive new tests for hardening verification, Aero Protocol compliance, and cache isolation.
- Format codebase with `ruff`.

…33388927676

Harden tests and code

- Resolved formatting issues in test files and core logic.
- Added missing NumPy-style docstrings and type hints to CLI and internal functions.
- Verified that all unit tests pass with both Eager and Lazy backends.
- Ensured compliance with the Aero Protocol for backend-agnostic computation.
- Verified that pre-commit hooks (ruff, ruff-format) pass completely.

…186392

Fix linting and CI issues for PR NOAA-EMC#94

Moved approximately 70 fragmented test files into 11 categorical files:
- test_backends.py
- test_diagnostics.py
- test_grids.py
- test_integration.py
- test_misc.py
- test_optimization.py
- test_protocol.py
- test_regridder.py
- test_unstructured.py
- test_utils.py
- test_viz.py

Each file contains migrated test functions and classes, with name conflicts
resolved by appending suffixes. Shared fixtures like dask_client and
sample_input were preserved. All original test_aero_*.py and other redundant
test files were removed to improve repository structure and maintainability.

…8799792

Consolidate and logically name test suite

- Add Architecture overview with Mermaid diagram to index.md
- Create Scientific Hygiene guide (Aero Protocol, NaN handling, diagnostics)
- Document xarray accessors in new accessors.md
- Complete missing grid generation utilities in utils.md
- Update navigation and examples README
- Fix SyntaxError and missing import in tests/test_utils.py

Harden Documentation and Scientific Guides

- Replace star imports with explicit imports in `tests/test_utils.py`.
- Fix bare except in `tests/test_utils.py`.
- Remove redundant empty test files that only contained star imports and no tests.
- Consolidate ESMF check logic in `tests/test_utils.py`.
- Ensure compliance with `ruff` linting rules.

…35715884

Fix linting issues in tests

- Update `.regrid.to()` to support passing a pre-computed `Regridder` instance, avoiding redundant weight generation.
- Add `.regrid.get_regridder()` to both DataArray and Dataset accessors to allow users to extract and reuse regridders.
- Add `.regrid.plot_diagnostics()` to accessors for rapid quality control.
- Ensure all new methods follow the Aero Protocol (backend-agnostic, strictly typed, NumPy docstrings).
- Add comprehensive tests in `tests/test_accessors.py` covering NumPy and Dask backends.

…8936950334624906

Optimize xarray accessors for weight reuse and diagnostics

…ask metadata extraction.

- Refactored `_get_non_spatial_dims` with expanded heuristics and cf-xarray standard names.
- Optimized stationary mask detection in `_apply_weights_core` while preserving early-exit heuristics.
- Consolidated `dask.compute` calls in `create_grid_like` to minimize scheduler roundtrips.
- Added comprehensive NumPy-style docstrings to all modified functions.
- Implemented protocol validation tests in `tests/test_aero_protocol.py`.

…50996168196

Aero Protocol Alignment and Performance Optimization