[1/N][refactor] torchair fused_moe refactor

[hust17yixuan]

What this PR does / why we need it?

Move torchair related fused_moe section into torchair_fused_moe to make the code clear. Next step we'll remove all torchair related code outside of torchair_fused_moe .

Does this PR introduce any user-facing change?

No

How was this patch tested?

vLLM version: v0.10.0
vLLM main: vllm-project/vllm@08d5f71

• vLLM version: v0.10.0
• vLLM main: vllm-project/vllm@b4e9fd8

[gemini-code-assist]

Code Review

This pull request refactors the fused_moe logic for torchair by moving it into a new, dedicated file, vllm_ascend/torchair/ops/torchair_fused_moe.py. This is a good step towards better code organization. The changes in torchair_deepseek_v2.py correctly adopt the new refactored module. However, I've identified a critical issue in the newly created torchair_fused_moe.py file which appears to be a copy-paste error from the refactoring. This will cause a NameError at runtime and needs to be addressed.

[gemini-code-assist]

AscendUnquantizedFusedMoEMethod is not defined or imported in this file, which will lead to a NameError at runtime. Based on the refactoring, it seems the check should be against TorchairAscendUnquantizedFusedMoEMethod, which is defined in this file.

Suggested change

	if envs_ascend.VLLM_ASCEND_ENABLE_MOE_ALL2ALL_SEQ and isinstance(
	self.quant_method, AscendUnquantizedFusedMoEMethod):
	if envs_ascend.VLLM_ASCEND_ENABLE_MOE_ALL2ALL_SEQ and isinstance(
	self.quant_method, TorchairAscendUnquantizedFusedMoEMethod):

[github-actions]

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[codecov]

Codecov Report

❌ Patch coverage is 65.55091% with 247 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.54%. Comparing base (3629bc4) to head (e97ad15).

Files with missing lines	Patch %	Lines
vllm_ascend/torchair/ops/torchair_fused_moe.py	55.12%	245 Missing ⚠️
tests/ut/torchair/ops/test_torchair_fused_moe.py	98.80%	2 Missing ⚠️

❌ Your patch check has failed because the patch coverage (65.55%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2438      +/-   ##
==========================================
- Coverage   78.04%   77.54%   -0.50%     
==========================================
  Files         132      134       +2     
  Lines       17557    18270     +713     
==========================================
+ Hits        13702    14168     +466     
- Misses       3855     4102     +247     

Flag	Coverage Δ
unittests	77.54% <65.55%> (-0.50%)	⬇️

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