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

docs/specs/attunements/enchanter/systems/enchanting-spec.md

@@ -281,6 +281,7 @@ Same formula as Prepare stage (§4.5).
 | **Catalyst** | basicCatalyst | 40 |
 | | fireCatalyst | 55 |
 | | voidCatalyst | 75 |
+| | metalSpellFocus | 50 |
 | **Sword** | ironBlade | 30 |
 | | steelBlade | 40 |
 | | crystalBlade | 55 |
@@ -643,7 +644,7 @@ capacity). It affects:
 | `src/lib/game/crafting-prep.ts` | Prepare stage logic, disenchant recovery |
 | `src/lib/game/crafting-apply.ts` | Apply stage logic, free enchant, Pure Essence |
 | `src/lib/game/crafting-utils.ts` | Shared utilities, capacity cost, cancellation refund |
-| `src/lib/game/crafting-attunements.ts` | Attunement-crafting integration, enchanting XP |
+| `src/lib/game/data/attunements.ts` | Attunement-crafting integration, enchanting XP |
 | `src/lib/game/data/enchantments/` | All enchantment effect definitions (7 categories) |
 | `src/lib/game/crafting-actions/design-actions.ts` | Design stage store actions |
 | `src/lib/game/crafting-actions/preparation-actions.ts` | Prepare stage store actions |