[Speculators][Speculative Decoding] Add Eagle3 Support For HunYuan Model

[kzjeef]

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• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.

Purpose

Add Eagle3 support for Hunyuan V1 models.

Test Plan

1. End 2 End Unit test

pytest -s vllm/tests/v1/e2e/test_spec_decode.py -k hunyuan

2. Service

uv run python3 -m vllm.entrypoints.openai.api_server --tensor-parallel-size 1 \
        --port 8000 \
        --speculative_config '{"model": "AngelSlim/Hunyuan-1.8B-Instruct_eagle3", "method" : "eagle3", "draft_tensor_parallel_size" : 1,  "num_speculative_tokens": 2}' --trust-remote-code \
        --model  tencent/Hunyuan-1.8B-Instruct 

Test Result

1. End 2 End Unit test
   ======================= 1 passed, 5 deselected in 51.72s =======================

2. Service

(Optional) Documentation Update

[github-actions]

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[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @kzjeef.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[gemini-code-assist]

Code Review

This pull request adds support for Eagle3 speculative decoding to the HunYuan model. The changes are extensive, touching model definitions, configuration, and tests. The core logic for Eagle3 support seems to be implemented in a new file hunyuan_v1_eagle3.py and by modifying hunyuan_v1.py to support auxiliary hidden states.

My review has identified a few critical and high-severity issues:

• A potential TypeError in hunyuan_v1.py due to an unhandled None value, which could cause a crash.
• Inappropriate use of inheritance in the new hunyuan_v1_eagle3.py model, which will make the code harder to maintain.
• A missing type hint in hunyuan_v1.py that was removed instead of being updated.
• Incomplete test data in tests/models/registry.py which will likely break some tests.

I've provided detailed comments and suggestions for these issues. Addressing them will improve the correctness and maintainability of the code.

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @kzjeef.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[DarkLight1337]

Thanks, the code LGTM now

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @kzjeef.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork