feat: add local weight synchronization to CheckpointEngineManager

[kevssim]

PR type

• Bug Fix
• New Feature
• Document Updates
• More Models or Datasets Support

PR information

Write the detail information belongs to this PR.

• Introduce mode: auto, naive, colocate, and standalone.
• In naive mode, local model and sampler objects synchronize weights directly through a generator without creating a checkpoint engine.
• Keep CUDA IPC for explicit colocate Ray deployments and NCCL/HCCL for standalone deployments.
• auto selects naive for local objects and standalone for Ray actor handlers.
• Update Transformers/Megatron models and vLLM/SGLang samplers for direct generator-based synchronization.

[tastelikefeet]

Now the branch is a draft, you can directly merge into it.

[kevssim]

Now the branch is a draft, you can directly merge into it.现在这个分支是草稿状态，你可以直接合并进去。

我还需要对代码进行一些测试和修改，完成后合入