AgentProcessAccessor

Accessor for AgentProcess ThreadLocal storage.

Used by ExecutorAsyncer to propagate AgentProcess context from the calling thread to worker threads. Each thread has its own ThreadLocal storage - this accessor provides the read/write operations to copy values between threads.

Flow:

1. Main thread: getValue captures current AgentProcess

2. Worker thread: setValue sets the captured value

3. Worker thread: block executes with access to AgentProcess

4. Worker thread: reset cleans up to prevent stale values