fix: resolve enchanting spec vs code discrepancies (issue #324)

- D2: Move spell_iceShard to basic-spells.ts at cost 75 (canonical), remove duplicate from frost-spells.ts
- D7: disenchantEquipment now adds 'Ready for Enchantment' tag and resets rarity to 'common'
- D8: disenchantEquipment now credits recovered mana to raw mana pool
- D14: Wire enchantPower stat from discipline effects into efficiencyBonus via new getEnchantingEfficiencyBonus() helper
- D3: Fix spec file reference from crafting-attunements.ts to data/attunements.ts
- D1/D6: Add missing metalSpellFocus to spec capacity table

src/lib/game/data/enchantments/spell-effects/frost-spells.ts

@@ -15,16 +15,6 @@ export const FROST_SPELL_EFFECTS: Record<string, EnchantmentEffectDef> = {
     allowedEquipmentCategories: ALL_CASTER,
     effect: { type: 'spell', spellId: 'frostBite' }
   },
-  spell_iceShard: {
-    id: 'spell_iceShard',
-    name: 'Ice Shard',
-    description: 'Grants the ability to cast Ice Shard (18 frost damage, freeze)',
-    category: 'spell',
-    baseCapacityCost: 95,
-    maxStacks: 1,
-    allowedEquipmentCategories: ALL_CASTER,
-    effect: { type: 'spell', spellId: 'iceShard' }
-  },
   spell_frostNova: {
     id: 'spell_frostNova',
     name: 'Frost Nova',