feat(eval): add model cache controls

[xieofxie]

Summary

• add canonical cache and rebuild controls to winml eval with cache reuse enabled by default
• carry cache policy through eval config and both Hugging Face and ONNX model loading
• derive ignored-control warnings from the same loader selection used by evaluation and identify config-file values by their actual source
• serialize resolved cache controls explicitly and cover Click defaults plus CLI-over-config precedence
• document the distinction between model build caching and GenAI runtime compilation caching

Review notes

• ignored_build_flags_warning now accepts the positive build_runs predicate instead of the former inverse skip_build_onnx predicate; all call sites were inverted with the rename.
• GenAI _compiled/ cache controls are tracked separately in Honor cache controls for GenAI runtime compilation #1275.
• The canonical perf cache migration is handled by stacked PR feat(perf): standardize cache controls #1271.

Stack

Shared cache primitives landed in #1269.

[zhenchaoni]

Reviewed the cache-control plumbing end to end and ran the affected suites on this branch (tests/unit/commands/test_eval.py, tests/unit/eval/test_eval.py, tests/unit/utils/test_cli.py, tests/unit/commands/test_perf_cli.py — 342 passed).

The core wiring is sound and the precedence outcome is currently correct. My main concerns are:

1. The GenAI path is classified as "no build runs", but it does build and cache (bundle_dir/_compiled/). Cache controls are silently dropped there and the user is told they were ignored. This one looks like a real bug.
2. _model_build_skip_reason re-implements _load_model's dispatch with different predicates, so the two can disagree.
3. ignored_build_flags_warning changed a keyword's name and inverted its meaning in one step — worth a second pair of eyes on the two call sites.
4. The stated precedence chain has no "CLI default" layer — it works today only because the Click defaults happen to equal the dataclass defaults, and nothing enforces that.

Details inline.