Refactor large files into modular components

- Refactored page.tsx (613→252 lines) with GameOverScreen and LeftPanel extracted
- Refactored StatsTab.tsx (584→92 lines) with section components
- Refactored SkillsTab.tsx (434→54 lines) with sub-components
- Created modular structure for GameContext, LootInventory, and other components
- All extracted components organized into feature directories

src/lib/game/data/equipment/utils.ts

@@ -0,0 +1,62 @@
+// ─── Equipment Helper Functions ─────────────────────────
+
+import type { EquipmentType, EquipmentSlot, EquipmentCategory } from './types';
+import { EQUIPMENT_TYPES } from './index';
+
+export function getEquipmentType(id: string): EquipmentType | undefined {
+  return EQUIPMENT_TYPES[id];
+}
+
+export function getEquipmentByCategory(category: EquipmentCategory): EquipmentType[] {
+  return Object.values(EQUIPMENT_TYPES).filter(e => e.category === category) as EquipmentType[];
+}
+
+export function getEquipmentBySlot(slot: EquipmentSlot): EquipmentType[] {
+  return Object.values(EQUIPMENT_TYPES).filter(e => e.slot === slot) as EquipmentType[];
+}
+
+export function getAllEquipmentTypes(): EquipmentType[] {
+  return Object.values(EQUIPMENT_TYPES) as EquipmentType[];
+}
+
+// Get valid slots for a category
+// Note: For 2-handed weapons, use getValidSlotsForEquipmentType instead
+export function getValidSlotsForCategory(category: EquipmentCategory): EquipmentSlot[] {
+  switch (category) {
+    case 'caster':
+    case 'catalyst':
+    case 'sword':
+      return ['mainHand'];
+    case 'shield':
+      return ['offHand'];
+    case 'head':
+      return ['head'];
+    case 'body':
+      return ['body'];
+    case 'hands':
+      return ['hands'];
+    case 'feet':
+      return ['feet'];
+    case 'accessory':
+      return ['accessory1', 'accessory2'];
+    default:
+      return [];
+  }
+}
+
+// Get valid slots for a specific equipment type (considers 2-handed weapons)
+export function getValidSlotsForEquipmentType(equipType: EquipmentType): EquipmentSlot[] {
+  // 2-handed weapons occupy both main hand and offhand
+  if (equipType.twoHanded) {
+    return ['mainHand', 'offHand'];
+  }
+  
+  // Otherwise use category-based slots
+  return getValidSlotsForCategory(equipType.category);
+}
+
+// Check if an equipment type can be equipped in a specific slot
+export function canEquipInSlot(equipmentType: EquipmentType, slot: EquipmentSlot): boolean {
+  const validSlots = getValidSlotsForEquipmentType(equipmentType);
+  return validSlots.includes(slot);
+}