Add reaction engine and action skeletons

scripts/conditions/damage-condition.js

@@ -0,0 +1,21 @@
+export async function checkDamageCondition(config, context) {
+  const amount = Number(context.amount ?? context.damageAmount ?? 0);
+  const absoluteAmount = Math.abs(amount);
+
+  if (absoluteAmount < (Number(config.minAmount) || 0)) return false;
+
+  if (config.amountMode === "damageOnly" && amount <= 0) return false;
+  if (config.amountMode === "healingOnly" && amount >= 0) return false;
+
+  if (config.amountMode === "healingOnly") return true;
+
+  const configuredTypes = config.types ?? [];
+  if (!configuredTypes.length) return true;
+
+  const eventTypes = new Set(context.damageTypes ?? []);
+  if (!eventTypes.size) return false;
+
+  if (config.typeMode === "all") return configuredTypes.every(type => eventTypes.has(type));
+  if (config.typeMode === "none") return configuredTypes.every(type => !eventTypes.has(type));
+  return configuredTypes.some(type => eventTypes.has(type));
+}

scripts/conditions/hp-threshold-condition.js

@@ -0,0 +1,21 @@
+export async function checkHpAfterDamageCondition(config, context) {
+  const actor = context.targetActor ?? context.actor;
+  if (!actor) return false;
+
+  const hp = actor.system?.attributes?.hp;
+  const value = Number(hp?.value ?? 0);
+  const max = Number(hp?.max ?? 0);
+  if (max <= 0) return false;
+
+  const actual = config.mode === "percent" ? (value / max) * 100 : value;
+  const threshold = Number(config.value ?? 0);
+
+  switch (config.operator ?? "lte") {
+    case "lt": return actual < threshold;
+    case "lte": return actual <= threshold;
+    case "gt": return actual > threshold;
+    case "gte": return actual >= threshold;
+    case "eq": return actual === threshold;
+    default: return actual <= threshold;
+  }
+}