fix(agent chat processor): add flow collect to improve concurrency

The `CustomAgentChatProcessor` now uses `kotlinx.coroutines.flow.collect` to process chat messages in a more concurrent and efficient manner, reducing the potential for blocking operations and improving overall system responsiveness.

Author: phodal

src/main/kotlin/cc/unitmesh/devti/agent/CustomAgentChatProcessor.kt

@@ -14,6 +14,7 @@ import com.intellij.openapi.components.service
 import com.intellij.openapi.diagnostic.logger
 import com.intellij.openapi.project.Project
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.runBlocking
 
 @Service(Service.Level.PROJECT)