fix(graph): fix llmnode thread safety

[mengnankkkk]

Describe what this PR does / why we need it

fix llmnode thread safety the message is thread unsafe

Does this pull request fix one issue?

Close #2510

Describe how you did it

Create copies of local variables to handle state

Describe how to verify it

Special notes for reviews

[mengnankkkk]

This way to slove one node,will change it

[Copilot]

Pull Request Overview

This PR fixes thread safety issues in the CompiledGraph class by changing from storing pre-created node instances to storing node factory functions. This ensures that each request gets a fresh instance, preventing shared state issues in concurrent environments.

Key changes:

• Replace the nodes map storing AsyncNodeActionWithConfig instances with nodeFactories map storing Node.ActionFactory functions
• Update all references to create new instances on-demand using the factories
• Add comprehensive test coverage for concurrent node creation scenarios

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
CompiledGraph.java	Core thread safety fix - replaces instance storage with factory pattern
NodeFactoryPatternTest.java	New test suite verifying factory pattern and concurrent access behavior

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[Copilot]

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

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