Add createCombatFromRun to create combat state from run

src/state.js

@@ -73,6 +73,48 @@ export function createCombatState(characterOrChars, enemyIdOrIds) {
   return state;
 }
 
+export function createCombatFromRun(run, enemyIdOrIds) {
+  const enemyIds = Array.isArray(enemyIdOrIds) ? enemyIdOrIds : [enemyIdOrIds];
+  const enemies = enemyIds.map((id, i) => makeEnemy(id, i));
+
+  const player = {
+    id: "player_0",
+    character: run.character,
+    hp: run.hp,
+    maxHp: run.maxHp,
+    energy: 3,
+    maxEnergy: 3,
+    block: 0,
+    strength: 0,
+    vulnerable: 0,
+    weak: 0,
+    drawPile: shuffle([...run.deck]),
+    hand: [],
+    discardPile: [],
+    exhaustPile: [],
+    powers: [],
+  };
+
+  const state = {
+    players: [player],
+    enemies,
+    combat: {
+      turn: 1,
+      phase: "player_turn",
+      dieResult: null,
+      selectedCard: null,
+      log: [],
+      playerCount: 1,
+      activePlayerIndex: null,
+      playersReady: [],
+    },
+  };
+
+  state.player = player;
+  state.enemy = enemies[0];
+  return state;
+}
+
 export function drawCards(state, playerIndexOrCount, count) {
   // drawCards(state, count) — old single-player form
   // drawCards(state, playerIndex, count) — new indexed form

src/state.test.js

@@ -1,7 +1,14 @@
 import { beforeAll, describe, expect, test } from "bun:test";
 import { initCards } from "./cards.js";
 import { initEnemies } from "./enemies.js";
-import { createCombatState, drawCards, endTurn, playCard } from "./state.js";
+import { createRunState } from "./run.js";
+import {
+  createCombatFromRun,
+  createCombatState,
+  drawCards,
+  endTurn,
+  playCard,
+} from "./state.js";
 
 beforeAll(async () => {
   await Promise.all([initCards(), initEnemies()]);
@@ -278,3 +285,34 @@ describe("backward compat - single string args", () => {
     expect(next.player.hand).toHaveLength(0);
   });
 });
+
+describe("createCombatFromRun", () => {
+  test("uses run deck for draw pile", () => {
+    const run = createRunState("ironclad");
+    // simulate picking a reward card
+    const modified = { ...run, deck: [...run.deck, "pommel_strike"] };
+    const state = createCombatFromRun(modified, "jaw_worm");
+    const allCards = [
+      ...state.players[0].drawPile,
+      ...state.players[0].hand,
+      ...state.players[0].discardPile,
+    ];
+    expect(allCards).toHaveLength(11);
+    expect(allCards.filter((id) => id === "pommel_strike")).toHaveLength(1);
+  });
+
+  test("uses run HP instead of max", () => {
+    const run = createRunState("ironclad");
+    run.hp = 7;
+    const state = createCombatFromRun(run, "jaw_worm");
+    expect(state.players[0].hp).toBe(7);
+    expect(state.players[0].maxHp).toBe(11);
+  });
+
+  test("backward-compat aliases work", () => {
+    const run = createRunState("ironclad");
+    const state = createCombatFromRun(run, "jaw_worm");
+    expect(state.player).toBe(state.players[0]);
+    expect(state.enemy).toBe(state.enemies[0]);
+  });
+});