docs(conductor): Synchronize docs for track 'Concurrent Tier Source Isolation'

conductor/tech-stack.md

@@ -41,6 +41,7 @@
 - **ApiHookClient:** A dedicated IPC client for automated GUI interaction and state inspection.
 - **mma-exec / mma.ps1:** Python-based execution engine and PowerShell wrapper for managing the 4-Tier MMA hierarchy and automated documentation mapping.
 - **dag_engine.py:** A native Python utility implementing `TrackDAG` and `ExecutionEngine` for dependency resolution, cycle detection, transitive blocking propagation, and programmable task execution loops.
+- **Thread-Local Context Isolation:** Utilizes `threading.local()` for managing per-thread AI client context (e.g., source tier tagging), ensuring thread safety during concurrent multi-agent execution.
 
 ## Architectural Patterns