fix: resolve 3 critical bugs — #354 attunement ReferenceError, #353 preparation mana exploit, #352 golem mana wipe

- #354: unlockAttunement now uses _get() instead of undefined 'state' variable
- #353: startPreparing now deducts raw mana from the mana store after validation
- #352: processGolemAttacks/processBasicAttack accept current mana as params instead of initializing to 0/{}
- Updated golem-combat-actions.test.ts to pass new currentRawMana/currentElements params
- Added regression tests for all 3 bugs (16 new tests, all passing)

src/lib/game/stores/golem-combat-helpers.ts

@@ -95,9 +95,9 @@ export interface BasicAttackResult {
  * AoE frames distribute damage across up to frame.aoeTargets enemies (spec §11).
  * Single-target frames attack the lowest-HP enemy.
  */
-export function processBasicAttack(ctx: BasicAttackContext): BasicAttackResult {
-  let rawMana = 0;
-  let elements: Record<string, { current: number; max: number; unlocked: boolean }> = {};
+export function processBasicAttack(ctx: BasicAttackContext, currentRawMana: number, currentElements: Record<string, { current: number; max: number; unlocked: boolean }>): BasicAttackResult {
+  let rawMana = currentRawMana;
+  let elements: Record<string, { current: number; max: number; unlocked: boolean }> = { ...currentElements };
   let floorHP = 0;
   let floorMaxHP = 0;
   let totalDamageDealt = 0;
@@ -174,6 +174,8 @@ export function processGolemAttacksFromStore(
   enemyElement: string,
   get: () => CombatStore,
   set: (s: Partial<CombatState>) => void,
+  currentRawMana: number,
+  currentElements: Record<string, { current: number; max: number; unlocked: boolean }>,
 ): GolemCombatResult {
   return processGolemAttacks(
     activeGolems,
@@ -212,5 +214,7 @@ export function processGolemAttacksFromStore(
       });
       set({ currentRoom: { ...room, enemies: updatedEnemies } });
     },
+    currentRawMana,
+    currentElements,
   );
 }