enhance a2o control and river map handling

[whannah1]

This pull request adds support for generating land↔river coupling maps (in addition to existing ocean and land maps), introduces per-component configuration for the direction of the --a2o switch to ensure correct grid ordering, and allows specifying remap algorithms per component. It also updates documentation and tests to reflect these new features.

Major new features and improvements:

1. Land↔River Coupling Map Generation

• Adds a new create_maps_rof function to generate river coupling maps between land and river grids, only when grid.rof_file is set. The river grid is now paired with the land grid, matching the actual coupling, and the logic ensures only one grid entry generates these maps. [1] [2] [3] [4]

2. Per-Component --a2o Direction Control

• Introduces grid.ocn_flip_a2o_direction, grid.lnd_flip_a2o_direction, and grid.rof_flip_a2o_direction settings in project.yaml and code, allowing each component to control which direction gets the --a2o switch. This prevents errors in TempestRemap due to incorrect grid ordering, especially for cases where the component grid is coarser than its reference grid. [1] [2] [3] [4] [5] [6]

3. Per-Component Remap Algorithm Selection

• Enhances algorithm selection to allow specifying remap algorithms per component (e.g., maps.algorithms.rof: [traave]), with sensible defaults (only conservative for river maps). This enables more flexible and concise configuration. [1] [2] [3]

Documentation and Testing:

4. Documentation Updates

• Updates docstrings and comments throughout taos/maps.py to document the new river map logic, per-component --a2o control, and algorithm selection. [1] [2] [3]

5. Expanded Unit Tests

• Adds comprehensive tests for the new _resolve_algorithms and _resolve_flip_a2o helpers, as well as for the new river map logic and --a2o direction switching. [1] [2] [3]