fix: round-trip match objectives through ScenarioSerializer

tests/Unit/Application/ScenarioSerializerTest.php

@@ -135,4 +135,41 @@ final class ScenarioSerializerTest extends TestCase
             // missing 'name', 'battlefield', 'units', etc.
         ]);
     }
+
+    public function testMatchRoundTripsItsObjectives(): void
+    {
+        $battlefield = new Battlefield(10, 8);
+        $units = [
+            new UnitState('a1', 'alpha', new Position(0, 0), 10, 10, 3, 3, 2, 2, false),
+            new UnitState('a2', 'alpha', new Position(1, 0), 10, 10, 3, 3, 2, 2, false),
+            new UnitState('a3', 'alpha', new Position(2, 0), 10, 10, 3, 3, 2, 2, false),
+            new UnitState('b1', 'bravo', new Position(9, 7), 10, 10, 3, 3, 2, 2, false),
+            new UnitState('b2', 'bravo', new Position(8, 7), 10, 10, 3, 3, 2, 2, false),
+            new UnitState('b3', 'bravo', new Position(7, 7), 10, 10, 3, 3, 2, 2, false),
+        ];
+        $objective = new ObjectiveMarker('objective-1', new Position(5, 4));
+        $original = new MatchState(
+            battlefield: $battlefield,
+            units: $units,
+            activeTeamId: 'alpha',
+            objectives: ['objective-1' => $objective],
+            victoryCondition: VictoryCondition::HoldObjective,
+            holdRoundsRequired: 3,
+        );
+
+        $array = ScenarioSerializer::matchToArray($original);
+        self::assertArrayHasKey('objectives', $array);
+        self::assertSame(
+            ['id' => 'objective-1', 'position' => ['x' => 5, 'y' => 4]],
+            $array['objectives']['objective-1'] ?? null,
+        );
+
+        $rebuilt = ScenarioSerializer::matchFromArray($array);
+        self::assertArrayHasKey('objective-1', $rebuilt->objectives);
+        self::assertSame('objective-1', $rebuilt->objectives['objective-1']->id);
+        self::assertSame(5, $rebuilt->objectives['objective-1']->position->x);
+        self::assertSame(4, $rebuilt->objectives['objective-1']->position->y);
+        self::assertSame(VictoryCondition::HoldObjective, $rebuilt->victoryCondition);
+        self::assertSame(3, $rebuilt->holdRoundsRequired);
+    }
 }