Speculative/EAGLE - Supported?

### Reminder

- [x] I have read the above rules and searched the existing issues.

### System Info

ktransformers @ bb15fdf
kvcache-ai/sglang @ 2763727

### Reproduction

```
[2026-05-15 19:00:54] Load weight end. elapsed=152.31 s, type=KimiK25ForConditionalGeneration, dtype=torch.bfloat16, avail mem=52.58 GB, mem usage=41.59 GB.
[2026-05-15 19:00:54] Using KV cache dtype: torch.bfloat16
[2026-05-15 19:00:54] KV Cache is allocated. #tokens: 260000, KV size: 17.02 GB
[2026-05-15 19:00:54] Memory pool end. avail mem=35.54 GB
[2026-05-15 19:00:54] Capture cuda graph begin. This can take up to several minutes. avail mem=35.10 GB
[2026-05-15 19:00:54] Capture cuda graph bs [1]
[2026-05-15 19:00:54] Scheduler hit an exception: Traceback (most recent call last):
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/managers/scheduler.py", line 3207, in run_scheduler_process
scheduler = Scheduler(
^^^^^^^^^^
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/managers/scheduler.py", line 367, in __init__
self.init_model_worker()
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/managers/scheduler.py", line 563, in init_model_worker
self.init_tp_model_worker()
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/managers/scheduler.py", line 521, in init_tp_model_worker
self.tp_worker = TpModelWorker(
^^^^^^^^^^^^^^
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/managers/tp_worker.py", line 247, in __init__
self._init_model_runner()
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/managers/tp_worker.py", line 330, in _init_model_runner
self._model_runner = ModelRunner(
^^^^^^^^^^^^
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/model_executor/model_runner.py", line 418, in __init__
self.initialize()
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/model_executor/model_runner.py", line 633, in initialize
self.init_device_graphs()
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/model_executor/model_runner.py", line 2211, in init_device_graphs
self.graph_runner = graph_runners[self.device](self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/kt-test/.venv/lib/python3.12/site-packages/sglang/srt/model_executor/cuda_graph_runner.py", line 562, in __init__
self.model_runner.model.set_eagle3_layers_to_capture()
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/kt-test/.venv/lib/python3.12/site-packages/torch/nn/modules/module.py", line 1964, in __getattr__
raise AttributeError(
AttributeError: 'KimiK25ForConditionalGeneration' object has no attribute 'set_eagle3_layers_to_capture'

[2026-05-15 19:00:54] Received sigquit from a child process. It usually means the child failed.
test.sh: line 38: 1787672 Killed python -m sglang.launch_server --host 0.0.0.0 --port 31245 --model /mnt/aux/aux/model/Kimi-K2.6/moonshotai --kt-weight-path /mnt/aux/aux/model/Kimi-K2.6/moonshotai --kt-cpuinfer 96 --kt-threadpool-count 8 --kt-num-gpu-experts 12 --kt-method RAWINT4 --kt-max-deferred-experts-per-token 2 --kt-gpu-prefill-token-threshold 1200 --kt-enable-dynamic-expert-update --attention-backend flashinfer --trust-remote-code --mem-fraction-static 0.94 --context-length 200000 --max-running-requests 1 --prefill-max-requests 1 --max-total-tokens 200000 --enable-mixed-chunk --served-model-name Kimi-K2.6 --enable-p2p-check --disable-shared-experts-fusion --chunked-prefill-size 32768 --tool-call-parser kimi_k2 --reasoning-parser kimi_k2 --enable-hierarchical-cache --hicache-ratio 2 --hicache-size 0 --skip-server-warmup --speculative-algorithm EAGLE3 --speculative-draft-model-path /mnt/aux/aux/model/Kimi-K26-eagle3/AQ-MedAI --speculative-num-steps 3 --speculative-eagle-topk 1 --speculative-num-draft-tokens 4 --sleep-on-idle
```

### Others

I'd like to use/try EAGLE3 w/Kimi, e.g. the EAGLE3 model provided by [AQ-MedAI](https://huggingface.co/AQ-MedAI/Kimi-K26-eagle3).

Their model-card indicates it should work with sglang 0.5.10 (maybe others, it doesn't say it's a minimum nor maximum)

Expected: Works.
Observed: Does not work. (See trace above)

I tried transformers 5.8.0, 5.7.0, and 5.6.2, although the problem appears to be in the model implementation in sglang/src/models/kimi_k25 .

Additionally, since kt vendors the sglang module, I can't file any report there.

Additionally2, there is little clarity wrt. differences between _mainline_ sglang and _kt_ sglang. There are pulls/commits that "merge" from mainline but it's still vague in terms of what to expect.

Start with sglang/srt/model_executor/cuda_graph_runner.py and sglang/src/models/kimi_k25, then reproduce the failure using the reported EAGLE3 launch command. Trace why KimiK25ForConditionalGeneration lacks set_eagle3_layers_to_capture and compare the vendored sglang behavior with the stated sglang 0.5.10 expectation. Done means the Kimi EAGLE3 model starts successfully or the issue documents confirmed incompatibility and its scope.

Written by the indexing model from the issue text.