[Model] Support native Transformers ERNIE 4.5 VL

[AndreasKaratzas]

Summary

• Pin the immutable native Transformers snapshot instead of mutable remote code that performs an unbounded font download during import.
• Bridge the native composite text, vision, MoE, image, and video contracts while retaining legacy flat-config behavior.
• Preserve native image/video token identity, metadata, sizing, cache inputs, and caller-owned video buffers.

The Buildkite child failed before EngineCore startup while importing the remote processor. A separate job captured the exact network error at its timeout-free font request.

Validation

• Config, M-RoPE, and processor contracts: 17 passed.
• Exact native architecture initialization: 1 passed on MI355.
• Real-model evaluation verified all 12 BF16 shard checksums; image output was 5, text output was 42, all log probabilities were finite, and shutdown returned the GPU to baseline.
• Changed-file pre-commit passed.

Buildkite: Extra Initialization 4

Duplicate check: no open PR was found for native Transformers ERNIE 4.5 VL compatibility.

AI assistance: Codex assisted with investigation, implementation, and validation; Andreas directed the compatibility design and reviewed the resulting changes.