fix(datasets): require pipeline options instead of substituting wrong defaults

[Maryyyyyyyam142]

Closes #1412
The four dataset builders derive the same image-pipeline options from args, but disagree on how. build_coco reads most of them directly; build_roboflow_from_coco, build_roboflow_from_yolo and build_o365_raw use getattr with literal fallbacks — five of which contradict the real config default:

option	old fallback	actual default
square_resize_div_64	False	True (TrainConfig)
segmentation_head	False	True on every seg variant
multi_scale	False	True (TrainConfig)
expanded_scales	False	True (TrainConfig)
patch_size	16	variant-dependent — 12 seg/keypoint, 14 base
num_windows	4	2 on every released variant

patch_size and num_windows have no default on ModelConfig, so no constant is correct — and (16, 4) matches no shipped variant.

Change

All four builders now read these seven options directly, so an incomplete namespace raises AttributeError instead of silently building a different pipeline. do_random_resize_via_padding is included for cluster parity; its fallback already matched the default, so that one is a no-op.

The remaining getattr fallbacks are deliberately untouched — aug_config, scale_jitter and augmentation_backend match their config default, and the keypoint fields' absence is meaningful ("detection-only", per the existing comment at coco.py:1301).

Scope

Latent on the RFDETRDataModule path: _namespace_from_configs populates every field, so normal model.train(...) is unaffected. The exposure is the direct-call path, which the builders' re-export from rfdetr.datasets and the comment at coco.py:1318-1322 both document as supported.

Tests

New tests/datasets/test_builder_options.py covers the cross-builder contract:

• each of the four builders raises on a namespace missing a pipeline option (fails on develop)
• the configured values reach the transform builder — num_windows=2 not 4, multi_scale=True, seg variants at patch_size=12 with include_masks=True

Four tests in test_coco.py passed partial namespaces and relied on the old fallbacks. They now use a _pipeline_args helper that spells out the values those fallbacks used to produce, so their behavior is unchanged and what they depend on is visible.

674 passed across tests/datasets/ and src/rfdetr/datasets/. ruff, ruff format, docformatter and codespell pass on the changed files; mypy reports nothing in them.