feat: implement golemancy combat system (spec §6, §9)

- Add ActiveGolem interface and activeGolems to GolemancyState
- Add maxRoomDuration to all 12 golem definitions
- Create golem-combat-actions.ts with pure golem combat logic (summoning, maintenance, attacks, room-duration)
- Create golem-combat.ts pipeline for golem combat setup
- Wire golem maintenance and attacks into processCombatTick
- Wire golem summoning into advanceRoomOrFloor on room entry
- Wire golem room-duration countdown into onFloorCleared callback
- Update combat-actions tests for new processCombatTick signature
- All 921 tests pass, all files under 400-line limit

Closes #259

src/lib/game/stores/combatStore.ts

@@ -4,7 +4,7 @@
 import { create } from 'zustand';
 import { persist } from 'zustand/middleware';
 import { createSafeStorage } from '../utils/safe-persist';
-import type { GameAction, SpellState, FloorState, GolemancyState, ActivityLogEntry, AchievementState, EquipmentSpellState, ActivityEventType } from '../types';
+import type { GameAction, SpellState, FloorState, GolemancyState, ActivityLogEntry, AchievementState, EquipmentSpellState, ActivityEventType, ActiveGolem } from '../types';
 import { getFloorMaxHP } from '../utils';
 import { generateFloorState } from '../utils/room-utils';
 import { addActivityLogEntry } from '../utils/activity-log';
@@ -55,6 +55,7 @@ export const useCombatStore = create<CombatStore>()(
       golemancy: {
         enabledGolems: [],
         summonedGolems: [],
+        activeGolems: [],
         lastSummonFloor: 0,
       },
 
@@ -189,6 +190,7 @@ export const useCombatStore = create<CombatStore>()(
           currentRoomIndex: 0,
           roomsPerFloor: 1,
           maxFloorReached: Math.max(s.maxFloorReached, 1),
+          golemancy: { ...s.golemancy, activeGolems: [], summonedGolems: [] },
         }));
       },
 
@@ -298,6 +300,8 @@ export const useCombatStore = create<CombatStore>()(
         onFloorCleared: (floor: number, wasGuardian: boolean) => void,
         onDamageDealt: (damage: number) => { rawMana: number; elements: Record<string, { current: number; max: number; unlocked: boolean }> },
         signedPacts: number[],
+        golemancyState: { activeGolems: ActiveGolem[] },
+        golemApplyDamageToRoom: (dmg: number) => { floorHP: number; floorMaxHP: number; roomCleared: boolean },
       ) => {
         return processCombatTick(
           get,
@@ -309,6 +313,8 @@ export const useCombatStore = create<CombatStore>()(
           onFloorCleared,
           onDamageDealt,
           signedPacts,
+          golemancyState,
+          golemApplyDamageToRoom,
         );
       },