Add area tactic effects

tools/validate_data.ps1

@@ -102,6 +102,7 @@ $validSkillTargets = @("enemy", "ally", "self", "any")
 $validSkillStats = @("atk", "def", "int", "agi")
 $validStatusStats = @("atk", "def", "int", "agi", "move")
 $validSkillEffectTypes = @("stat_bonus", "damage_over_time", "action_lock")
+$validSkillAreaShapes = @("single", "diamond")
 $validDialogueSides = @("left", "right")
 $validPortraitPathPattern = '^res://.+\.(png|jpg|jpeg|webp)$'
 $knownFlagIds = New-Object System.Collections.Generic.HashSet[string]
@@ -774,6 +775,20 @@ function Check-Skill-Definitions() {
             Fail "Skill $skillId has unknown target: $target"
         }
         Check-Skill-Range (Get-Prop $skill "range" 1) "Skill $skillId"
+        $areaShape = [string](Get-Prop $skill "area_shape" "single")
+        if (-not $validSkillAreaShapes.Contains($areaShape)) {
+            Fail "Skill $skillId has unsupported area_shape: $areaShape"
+        }
+        $areaRadius = [int](Get-Prop $skill "area_radius" 0)
+        if ($areaRadius -lt 0) {
+            Fail "Skill $skillId has invalid area_radius."
+        }
+        if ($areaShape -eq "single" -and $areaRadius -gt 0) {
+            Fail "Skill $skillId area_radius requires a non-single area_shape."
+        }
+        if ($areaShape -ne "single" -and $areaRadius -le 0) {
+            Fail "Skill $skillId area_shape requires a positive area_radius."
+        }
         if ([int](Get-Prop $skill "mp_cost" 0) -lt 0) {
             Fail "Skill $skillId has negative mp_cost."
         }