fix cross-process scenario switching and stale flights on scenario change

agents/shared/mcp_client.py

@@ -12,8 +12,9 @@ from fastmcp import Client
 
 
 def _env() -> dict:
-    """Forward LLM-related env vars to MCP server subprocesses."""
+    """Forward LLM-related env vars and active scenario to MCP server subprocesses."""
     import os
+    from mcp_servers.data.scenarios.manager import scenario_manager
 
     env = {}
     for key in (
@@ -27,6 +28,7 @@ def _env() -> dict:
         val = os.getenv(key)
         if val:
             env[key] = val
+    env["ACTIVE_SCENARIO"] = scenario_manager.active_id
     return env