Move mission generation code into game.

Operation has been renamed MissionGenerator and is no longer a static
class.

game/ato/flighttype.py

@@ -16,7 +16,7 @@ class FlightType(Enum):
 
     * flightplan.py: Add waypoint population in generate_flight_plan. Add a new flight
       plan type if necessary, though most are a subclass of StrikeFlightPlan.
-    * aircraft.py: Add a configuration method and call it in setup_flight_group. This is
+    * aircraftgenerator.py: Add a configuration method and call it in setup_flight_group. This is
       responsible for configuring waypoint 0 actions like setting ROE, threat reaction,
       and mission abort parameters (winchester, bingo, etc).
     * Implementations of MissionTarget.mission_types: A mission type can only be planned
@@ -28,7 +28,7 @@ class FlightType(Enum):
     You may also need to update:
 
     * flightwaypointtype.py: Add a new waypoint type if necessary. Most mission types
-      will need these, as aircraft.py uses the ingress point type to specialize AI
+      will need these, as aircraftgenerator.py uses the ingress point type to specialize AI
       tasks, and non-strike-like missions will need more specialized control.
     * ai_flight_planner.py: Use the new mission type in propose_missions so the AI will
       plan the new mission type.

game/ato/flightwaypoint.py

@@ -1,14 +1,18 @@
+from __future__ import annotations
+
 from datetime import timedelta
-from typing import Optional, Sequence, Union
+from typing import Optional, Sequence, TYPE_CHECKING, Union
 
 from dcs import Point
 from dcs.point import MovingPoint, PointAction
 from dcs.unit import Unit
 
-from game.theater import ControlPoint, MissionTarget
 from game.utils import Distance, meters
 from game.ato.flightwaypointtype import FlightWaypointType
 
+if TYPE_CHECKING:
+    from game.theater import ControlPoint, MissionTarget
+
 
 class FlightWaypoint:
     def __init__(

game/ato/flightwaypointtype.py

@@ -12,7 +12,7 @@ class FlightWaypointType(Enum):
     * waypointbuilder.py: Add a builder to simplify construction of the new waypoint
       type unless the new waypoint type will be a parameter to an existing builder
       method (such as how escort ingress waypoints work).
-    * aircraft.py: Associate AI actions with the new waypoint type by subclassing
+    * aircraftgenerator.py: Associate AI actions with the new waypoint type by subclassing
       PydcsWaypointBuilder and using it in PydcsWaypointBuilder.for_waypoint.
     """
 

game/ato/package.py

@@ -1,16 +1,20 @@
+from __future__ import annotations
+
 import logging
 from collections import defaultdict
 from dataclasses import dataclass, field
 from datetime import timedelta
-from typing import List, Optional, Dict
+from typing import List, Optional, Dict, TYPE_CHECKING
 
 from game.ato import Flight, FlightType
 from game.ato.packagewaypoints import PackageWaypoints
-from game.theater import MissionTarget
 from game.utils import Speed
 from gen.flights.flightplan import FormationFlightPlan
 from gen.flights.traveltime import TotEstimator
 
+if TYPE_CHECKING:
+    from game.theater import MissionTarget
+
 
 @dataclass
 class Package: