Add option for setting desired mission length.

game/settings.py

@@ -1,4 +1,5 @@
 from dataclasses import dataclass, field
+from datetime import timedelta
 from typing import Dict, Optional
 
 from dcs.forcedoptions import ForcedOptions
@@ -25,6 +26,9 @@ class Settings:
 
     default_start_type: str = "Cold"
 
+    # Mission specific
+    desired_player_mission_duration: timedelta = timedelta(minutes=90)
+
     # Campaign management
     automate_runway_repair: bool = False
     automate_front_line_reinforcements: bool = False