fix(@projects/@magic-civilization): 🐛 add result tracking flag for silent crash detection

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

src/game/engine/scenes/tests/auto_play.gd

@@ -69,6 +69,11 @@ var _turn_first_city_captured: int = -1
 var _event_buffer: Array[Dictionary] = []
 # Guards against writing terminal outcome line twice (e.g. victory during max_turns path)
 var _final_line_written: bool = false
+# True once at least one turn_stats line has been appended. Used by the E2E
+# gate to distinguish "game ran and wrote stats" from "game crashed silently
+# before producing any output" — a silent crash would leave turn_stats.jsonl
+# missing or empty, which the batch wrapper now rejects with a nonzero exit.
+var _result_written: bool = false
 
 
 func _ready() -> void:

src/game/engine/src/modules/ai/simple_heuristic_ai.gd

@@ -590,16 +590,15 @@ static func _decide_production(
 		# and is >20 turns old, pause military top-up to slot walls in. Walls
 		# were being starved indefinitely by the mil-floor above; a T40-50
 		# wall hardens the capital before the opponent's full army arrives.
-		var capital_age: int = (
-			GameState.turn_number - int(city.turn_founded)
-		)
-		var capital_needs_walls: bool = (
+		# Named distinctly from the outer `capital_needs_walls` because this
+		# branch applies a looser mil≥1 threshold for the interject.
+		var mil_floor_walls_interject: bool = (
 			city_count == 1 and city_index == 0
 			and military_count >= 1 and capital_age > 20
 			and not city.has_building("walls")
 			and city.can_build("walls", player)
 		)
-		if not capital_needs_walls:
+		if not mil_floor_walls_interject:
 			var emergency_unit: String = _pick_buildable_military_unit_id(
 				city, player
 			)