slimeys secret smithy vault

• A hidden deepslate/blackstone vault now spawns below plains village blacksmith houses. It builds as soon as the chunk containing the smithy generates or loads, keyed by a lodestone marker so it is only created once per location.
• Look for the trapdoor just east of the smithing table inside the blacksmith; a ladder drops into the underground room with workstations (smithing table, enchanting table, anvil, brewing/cartography tables, ender chest, shulker box, beacon decor) and bright lighting.
• Loot inside the chest includes fully enchanted netherite armor (prot/unbreaking/mending, boots with feather falling and depth strider), maxed netherite tools/weapons, a mending+unbreaking elytra, totems, enchanted golden apples, netherite ingots, ancient debris, diamond/emerald blocks, rockets, experience bottles, and a nether star. A nearby barrel holds extra travel and crafting supplies (obsidian, pearls, blaze rods, eyes, spectral arrows, food, catalysts, etc.).
• Generation targets smithing tables that sit near a blast furnace in plains-village biomes; if the original structure is heavily altered or the biome tag differs, the vault may not trigger. Removing the lodestone marker could allow a rebuild on a future load if the smithy remains.
• The room carves a 9x9 space roughly ten blocks beneath the blacksmith; ensure the surrounding area is clear of player builds before first load if you want to preserve underground projects.