[MODEL] support ovis2 6 moe

[ZX-ModelCloud]

Summary

1. support ovis2_6_moe
2. BaseQModel add field: defuser_module_paths
   Some models (e.g. ovis2_6_moe) do not contain MoE layers directly.
   The actual experts live inside submodules (e.g. Qwen3MoeModel.mlp.experts),
   so defuser_module_paths is used to explicitly locate and defuse them.

See https://huggingface.co/AIDC-AI/Ovis2.6-30B-A3B/blob/main/config.json:

{
  "architectures": [
    "Ovis2_6_MoeForCausalLM"
  ],
  ...
  "llm_config": {
    "_attn_implementation_autoset": true,
    "_name_or_path": "Qwen/Qwen3-30B-A3B-Thinking-2507",
    "architectures": [
      "Qwen3MoeForCausalLM"
    ],
    ...
   }
}