EMC for Iron's Spellbooks

v0.2.0

• Added EMC for all five alchemist ink tiers (common through legendary).
• Common ink is a root value (no recipe; chest loot and wandering traders only); the four tiers above it follow the cauldron's fixed four-to-one ladder.
• Bottle returns from the cauldron recipes are factored in, so each tier stays EMC-neutral or below.
• Elixirs remain unvalued (component-carrying potion bases, no item source for blood, and per-recipe brew ratios).
• Moved the mithril anchor from Raw Mithril to Mithril Scrap. ProjectE forces every item in the raw-materials tag to zero, so the old value never applied and the mithril chain went unpriced on 1.21.1. Smelting is one-to-one, so the value is unchanged.
• Dropped the Arcane Salvage value from the 1.21.1 build. Iron's Spellbooks 1.21.1 ships the item's assets but never registers it, so the entry only produced a load error. The Forge 1.20.1 build, where the item does exist, keeps it.