feat(combat): water traversal costs 3 and ends the turn

tests/Unit/Domain/MatchStateTest.php

@@ -56,7 +56,6 @@ final class MatchStateTest extends TestCase
      */
     public static function impassableTerrainProvider(): iterable
     {
-        yield 'water' => [Terrain::Water];
         yield 'blocking' => [Terrain::Blocking];
     }
 

tests/Unit/Domain/ScenarioValidatorTest.php

@@ -28,7 +28,7 @@ final class ScenarioValidatorTest extends TestCase
     public function testItRejectsAnObjectiveOnImpassableTerrain(): void
     {
         $scenario = $this->validScenario(
-            terrain: ['4:4' => Terrain::Water],
+            terrain: ['4:4' => Terrain::Blocking],
             objectivePosition: new Position(4, 4),
         );
 
@@ -81,7 +81,7 @@ final class ScenarioValidatorTest extends TestCase
     public function testItRejectsDeploymentPositionsOnImpassableTerrain(): void
     {
         $units = $this->unitSet();
-        $battlefield = new Battlefield(8, 8, ['0:0' => Terrain::Water]);
+        $battlefield = new Battlefield(8, 8, ['0:0' => Terrain::Blocking]);
         $scenario = new Scenario(
             id: 'demo',
             name: 'Demo',

tests/Unit/Domain/TerrainTest.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace BattleForge\Tests\Unit\Domain;
+
+use BattleForge\Domain\Terrain;
+use PHPUnit\Framework\TestCase;
+
+final class TerrainTest extends TestCase
+{
+    public function testOpenCostsOne(): void
+    {
+        self::assertSame(1, Terrain::Open->movementCost());
+        self::assertSame(0, Terrain::Open->defenseBonus());
+    }
+
+    public function testForestCostsTwoAndGivesOneDefense(): void
+    {
+        self::assertSame(2, Terrain::Forest->movementCost());
+        self::assertSame(1, Terrain::Forest->defenseBonus());
+    }
+
+    public function testRoughCostsTwoAndGivesNoDefense(): void
+    {
+        self::assertSame(2, Terrain::Rough->movementCost());
+        self::assertSame(0, Terrain::Rough->defenseBonus());
+    }
+
+    public function testWaterCostsThreeAndGivesNoDefense(): void
+    {
+        self::assertSame(3, Terrain::Water->movementCost());
+        self::assertSame(0, Terrain::Water->defenseBonus());
+    }
+
+    public function testBlockingIsImpassable(): void
+    {
+        self::assertNull(Terrain::Blocking->movementCost());
+    }
+}

tests/Unit/Domain/UnitStateTest.php

@@ -229,12 +229,32 @@ final class UnitStateTest extends TestCase
         self::assertFalse($started->hasUsedAbility);
     }
 
+    public function testStartTurnResetsWadedFlag(): void
+    {
+        $unit = $this->unit(wadedThisTurn: true);
+        $started = $unit->startTurn();
+        self::assertFalse($started->wadedThisTurn);
+    }
+
+    public function testWithWadedSetsAndClearsFlag(): void
+    {
+        $unit = $this->unit();
+        self::assertFalse($unit->wadedThisTurn);
+
+        $wading = $unit->withWaded(true);
+        self::assertTrue($wading->wadedThisTurn);
+
+        $dry = $wading->withWaded(false);
+        self::assertFalse($dry->wadedThisTurn);
+    }
+
     private function unit(
         int $health = 10,
         int $actionsRemaining = 2,
         bool $hasAttacked = false,
         int $attackBonus = 0,
         bool $hasUsedAbility = false,
+        bool $wadedThisTurn = false,
     ): UnitState {
         return new UnitState(
             'unit-1',