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/combat-actions.ts

@@ -6,8 +6,10 @@ import { SPELLS_DEF, HOURS_PER_TICK } from '../constants';
 import { getGuardianForFloor } from '../data/guardian-encounters';
 import type { CombatStore, CombatState } from './combat-state.types';
 import type { SpellState } from '../types';
+import type { ActiveGolem } from '../types';
 import { getFloorMaxHP, getFloorElement, getMultiElementBonus, calcDamage, canAffordSpellCost, deductSpellCost } from '../utils';
 import { computeDisciplineEffects } from '../effects/discipline-effects';
+import { processGolemMaintenance, processGolemAttacks } from './golem-combat-actions';
 
 /**
  * Create a default CombatTickResult for safe fallback on error.
@@ -16,6 +18,7 @@ function makeDefaultCombatTickResult(
   rawMana: number,
   elements: Record<string, { current: number; max: number; unlocked: boolean }>,
   state: CombatState,
+  activeGolems: ActiveGolem[],
 ): CombatTickResult {
   return {
     rawMana,
@@ -28,6 +31,7 @@ function makeDefaultCombatTickResult(
     maxFloorReached: state.maxFloorReached,
     castProgress: state.castProgress,
     equipmentSpellStates: state.equipmentSpellStates,
+    activeGolems,
   };
 }
 
@@ -42,6 +46,7 @@ export interface CombatTickResult {
   maxFloorReached: number;
   castProgress: number;
   equipmentSpellStates: CombatState['equipmentSpellStates'];
+  activeGolems: ActiveGolem[];
 }
 
 export function processCombatTick(
@@ -58,19 +63,63 @@ export function processCombatTick(
     modifiedDamage?: number;
   },
   signedPacts: number[],
+  golemancyState: { activeGolems: ActiveGolem[] },
+  golemApplyDamageToRoom: (dmg: number) => { floorHP: number; floorMaxHP: number; roomCleared: boolean },
 ): CombatTickResult {
   const state = get();
   const logMessages: string[] = [];
   let totalManaGathered = 0;
 
   if (state.currentAction !== 'climb') {
-    return makeDefaultCombatTickResult(rawMana, elements, state);
+    return makeDefaultCombatTickResult(rawMana, elements, state, golemancyState.activeGolems);
   }
 
+  // ─── Golem maintenance (spec §9.5) ──────────────────────────────────────
+  const maintenanceResult = processGolemMaintenance(
+    golemancyState.activeGolems,
+    rawMana,
+    elements,
+  );
+  let activeGolems = maintenanceResult.maintainedGolems;
+  rawMana = maintenanceResult.rawMana;
+  elements = maintenanceResult.elements;
+  logMessages.push(...maintenanceResult.logMessages);
+
+  // Write maintained golems back immediately so tick state stays consistent
+  set({ golemancy: { ...state.golemancy, activeGolems } });
+
   const spellId = state.activeSpell;
   const spellDef = SPELLS_DEF[spellId];
   if (!spellDef) {
-    return makeDefaultCombatTickResult(rawMana, elements, state);
+    // Even if no spell is configured, golems can still fight
+    // Process golem attacks even without a valid spell
+    if (activeGolems.length > 0) {
+      const golemAttackResult = processGolemAttacks(
+        activeGolems,
+        rawMana,
+        elements,
+        state.floorHP,
+        state.floorMaxHP,
+        state.currentFloor,
+        onDamageDealt,
+        golemApplyDamageToRoom,
+      );
+      rawMana = golemAttackResult.rawMana;
+      elements = golemAttackResult.elements;
+      activeGolems = golemAttackResult.activeGolems;
+      logMessages.push(...golemAttackResult.logMessages);
+
+      // Check if golems cleared the room
+      const newFloorHP = golemApplyDamageToRoom(0);
+      if (newFloorHP.roomCleared || golemAttackResult.totalDamageDealt > 0) {
+        // Re-check floor state after golem attacks
+        const newState = get();
+        if (newState.floorHP <= 0) {
+          return makeDefaultCombatTickResult(rawMana, elements, state, activeGolems);
+        }
+      }
+    }
+    return makeDefaultCombatTickResult(rawMana, elements, state, activeGolems);
   }
 
   try {
@@ -227,6 +276,32 @@ export function processCombatTick(
       updatedEquipmentSpellStates[i] = { ...eSpell, castProgress: eCastProgress % 1 };
     }
 
+    // ─── Golem attacks (spec §9.4) ─────────────────────────────────────────
+    // Golems attack after spells, using the same damage pipeline.
+    // They ignore Executioner/Berserker (handled internally by processGolemAttacks).
+    if (activeGolems.length > 0 && floorHP > 0) {
+      const golemResult = processGolemAttacks(
+        activeGolems,
+        rawMana,
+        elements,
+        floorHP,
+        floorMaxHP,
+        currentFloor,
+        onDamageDealt,
+        golemApplyDamageToRoom,
+      );
+      rawMana = golemResult.rawMana;
+      elements = golemResult.elements;
+      activeGolems = golemResult.activeGolems;
+      logMessages.push(...golemResult.logMessages);
+
+      // Read back floor state after golem damage
+      const postGolemState = get();
+      floorHP = postGolemState.floorHP;
+      floorMaxHP = postGolemState.floorMaxHP;
+      currentFloor = postGolemState.currentFloor;
+    }
+
     const newMaxFloorReached = Math.max(state.maxFloorReached, currentFloor);
 
     return {
@@ -240,12 +315,13 @@ export function processCombatTick(
       maxFloorReached: newMaxFloorReached,
       castProgress,
       equipmentSpellStates: updatedEquipmentSpellStates,
+      activeGolems,
     };
   } catch (error) {
     // Return safe defaults on error — combat tick should never crash the game
     const errorMsg = error instanceof Error ? error.message : String(error);
     logMessages.push(`⚠️ Combat error: ${errorMsg}`);
-    return makeDefaultCombatTickResult(rawMana, elements, state);
+    return makeDefaultCombatTickResult(rawMana, elements, state, activeGolems);
   }
 }