Add initiative rolls

module/combat.mjs

@@ -0,0 +1,36 @@
+import { rollInitiativeCheck } from "./rolls.mjs"
+
+/**
+ * Custom Combat class for Oath Hammer.
+ * Initiative = opposed Leadership check (DV=0).
+ * The number of successes becomes the combatant's initiative score.
+ */
+export default class OathHammerCombat extends Combat {
+  /**
+   * Override Foundry's rollInitiative to use Leadership skill checks.
+   * For characters: Leadership (Fate) opposed check, successes = score.
+   * For NPCs: Fate rank + initiative bonus pool.
+   *
+   * @param {string|string[]} ids   Combatant IDs to roll for
+   * @param {object}          options
+   */
+  async rollInitiative(ids, { formula = null, updateTurn = true, messageOptions = {} } = {}) {
+    const combatantIds = typeof ids === "string" ? [ids] : ids
+    const updates = []
+
+    for (const id of combatantIds) {
+      const combatant = this.combatants.get(id)
+      if (!combatant?.isOwner) continue
+      const actor = combatant.actor
+      if (!actor) continue
+
+      const { successes } = await rollInitiativeCheck(actor)
+      updates.push({ _id: id, initiative: successes })
+    }
+
+    if (!updates.length) return this
+    await this.updateEmbeddedDocuments("Combatant", updates)
+    if (updateTurn && this.turn !== null) await this.update({ turn: 0 })
+    return this
+  }
+}