Fix batch_func validation for invalid output coords

[fallintoplace]

Closes #889

Description

• reject invalid output_coords earlier in batch_func._compress_batch
• add a regression test for models whose output coordinates do not start with batch

Why

The existing guard only raised when both input_coords and output_coords were invalid. If input_coords was valid but output_coords was not, the call got past the compatibility check and later failed in _decompress_batch with KeyError: 'batch' instead of the intended early ValueError.\n\n## Impact\nThis makes the batching path fail fast with the compatibility error for misconfigured models and keeps the failure mode predictable.\n\n## Validation\n- uv run pytest 'test/models/test_batch.py::test_invalid_output_coords_raise' 'test/models/test_batch.py::test_invalid_ordering_raises[cpu]'\n- uv run ruff check earth2studio/models/batch.py test/models/test_batch.py

[greptile-apps]

Greptile Summary

Fixes a silent pass-through in batch_func._compress_batch where a model with valid input_coords but invalid output_coords (missing the leading "batch" key) would bypass the early guard and later crash with an opaque KeyError in _decompress_batch.

• The validation condition is corrected from and to or, so a ValueError is raised immediately if either coordinate system is missing "batch" as its first key.
• A new regression test (test_invalid_output_coords_raise) constructs a model that deletes "batch" from its output coords and asserts the expected ValueError is raised at call time.

Confidence Score: 5/5

Safe to merge — the one-character operator change is logically correct and directly addresses the described failure mode.

The change is minimal and well-reasoned: or correctly flags either coordinate system being misconfigured, while and only caught the case where both were wrong. The new test directly reproduces the previously-silent failure path and confirms the fix holds.

No files require special attention.

Important Files Changed

Filename	Overview
earth2studio/models/batch.py	Single-character logic fix: and → or in the batch-dimension guard, so a valid input_coords paired with an invalid output_coords now correctly raises ValueError instead of falling through to a KeyError later.
test/models/test_batch.py	Adds test_invalid_output_coords_raise — a focused regression test for the exact bug scenario where input_coords starts with "batch" but output_coords removes it, ensuring the ValueError is raised at compress time.

_{Reviews (1): Last reviewed commit: "Fix batch guard for invalid output coord..." | Re-trigger Greptile}