refactor: split bloated state types into State + Actions interfaces (issue #102)

- CombatState: split into CombatState (data) + CombatActions + CombatStore
- PrestigeState: split into PrestigeState (data) + PrestigeActions + PrestigeStore
- ManaState: split into ManaState (data) + ManaActions + ManaStore
- GameState: deprecated, removed from barrel exports
- crafting-actions: updated to use CraftingState instead of GameState
- combat-utils/mana-utils: replaced Pick<GameState,...> with focused interfaces
- DisciplineCardProps: split into Definition + Runtime + Callbacks
- stores/index.ts: now exports both State and Actions types

src/components/game/tabs/EquipmentTab.tsx

@@ -2,7 +2,6 @@
 
 import { useState, useEffect, useCallback, useMemo } from 'react';
 import { useCraftingStore } from '@/lib/game/stores/craftingStore';
-import { equipItem, unequipItem, deleteEquipmentInstance } from '@/lib/game/crafting-actions/equipment-actions';
 import type { EquipmentSlot } from '@/lib/game/types';
 import { DebugName } from '@/components/game/debug/debug-context';
 import { EquipmentSlotGrid } from './EquipmentTab/EquipmentSlotGrid';