Phase 6: Pokémon machines (five cores, shells as data)

Adrian (2026-10-31): a Large Furnace where a Fire Pokémon heats real
furnaces (hoppers in and out), our own Electric generator, no upkeep;
then a drop synthesizer (FE into full drop rolls, looting tiers), a
sacrifice altar (level tiers, rare candies only from Lv 80) and a
rebirth chamber (Lv 100 -> shiny Lv 1 first stage, three perfect IVs,
moves kept, Ability Patch so the hidden ability is optional).

- machine/: data-driven 3x3x3 shells (window spots for glass, free
  spot under the core), checked in four rotations; the Pokémon walks in
  from the party and lives in the core; breaking core or shell sends it
  home (party, else PC, offline too); a real Cobblemon entity copy is
  shown in the chamber (no AI, invulnerable, uncatchable, never saved).
- Heat Core keeps vanilla furnaces lit and faster; Dynamo Core makes
  and pushes FE; Synthesis Core takes FE and rolls drops into a hopper-
  extractable buffer; Altar Core sacrifices on a confirmed sneak-use;
  Rebirth Core runs on server time.
- Recipes, casing tags, block loot, textures (tools/machine_assets.py),
  models, blockstates, names.
- Self-tests: in/out, refusal, shell and core breaks (PC when full),
  chunk unload, server restart, and each machine's work.
- Docs: design, balance table, Phase 6 checklist; Phase 5 approved.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mod/src/main/kotlin/dev/cobblesurvival/machine/MachineDisplay.kt

@@ -0,0 +1,74 @@
+package dev.cobblesurvival.machine
+
+import com.cobblemon.mod.common.api.Priority
+import com.cobblemon.mod.common.api.events.CobblemonEvents
+import com.cobblemon.mod.common.api.events.battles.BattleStartedEvent
+import com.cobblemon.mod.common.entity.pokemon.PokemonEntity
+import com.cobblemon.mod.common.pokemon.Pokemon
+import com.cobblemon.mod.common.pokemon.properties.UncatchableProperty
+import net.minecraft.core.BlockPos
+import net.minecraft.core.Direction
+import net.minecraft.nbt.CompoundTag
+import net.minecraft.server.level.ServerLevel
+import net.minecraft.world.entity.Entity
+import net.neoforged.neoforge.common.NeoForge
+import net.neoforged.neoforge.event.entity.EntityJoinLevelEvent
+import net.neoforged.neoforge.event.entity.player.AttackEntityEvent
+import net.neoforged.neoforge.event.entity.player.PlayerInteractEvent
+import java.util.UUID
+
+/**
+ * The Pokémon a machine shows in its chamber (roadmap Phase 6: a real Cobblemon entity, so its own model and
+ * animations are used). It's a copy of the Pokémon kept in the core, with its own id, scaled to fit the chamber,
+ * without AI, invulnerable, silent, uncatchable, and it can't be used, hit or battled. It's never meant to be in the
+ * world save: one that comes back from disk is dropped, and the core puts a fresh one there.
+ */
+object MachineDisplay {
+    /** Key in the copy's persistent data; its value is the core's position. */
+    const val TAG = "cobblesurvival_machine"
+    /** The chamber is one block; leave a little room. */
+    private const val FIT = 0.9f
+
+    fun register() {
+        NeoForge.EVENT_BUS.addListener(::onJoin)
+        NeoForge.EVENT_BUS.addListener<PlayerInteractEvent.EntityInteract> { if (isDisplay(it.target)) it.isCanceled = true }
+        NeoForge.EVENT_BUS.addListener<PlayerInteractEvent.EntityInteractSpecific> { if (isDisplay(it.target)) it.isCanceled = true }
+        NeoForge.EVENT_BUS.addListener<AttackEntityEvent> { if (isDisplay(it.target)) it.isCanceled = true }
+        CobblemonEvents.BATTLE_STARTED_PRE.subscribe(Priority.HIGHEST, ::onBattle)
+    }
+
+    fun isDisplay(entity: Entity?): Boolean = entity is PokemonEntity && entity.pokemon.persistentData.contains(TAG)
+
+    fun spawn(level: ServerLevel, pokemon: Pokemon, core: BlockPos, chamber: BlockPos, facing: Direction): PokemonEntity {
+        val copy = Pokemon().loadFromNBT(level.registryAccess(), pokemon.saveToNBT(level.registryAccess(), CompoundTag()))
+        copy.uuid = UUID.randomUUID()
+        copy.persistentData.putLong(TAG, core.asLong())
+        UncatchableProperty.uncatchable().apply(copy)
+        val entity = PokemonEntity(level, copy)
+        val size = maxOf(entity.bbWidth, entity.bbHeight)
+        if (size > FIT) {
+            copy.scaleModifier = copy.scaleModifier * FIT / size
+            entity.refreshDimensions()
+        }
+        entity.setNoAi(true)
+        entity.setNoGravity(true)
+        entity.isInvulnerable = true
+        entity.isSilent = true
+        entity.setPersistenceRequired()
+        entity.busyLocks.add(this)
+        entity.moveTo(chamber.x + 0.5, chamber.y.toDouble(), chamber.z + 0.5, facing.toYRot(), 0f)
+        entity.yHeadRot = facing.toYRot()
+        entity.yBodyRot = facing.toYRot()
+        level.addFreshEntity(entity)
+        return entity
+    }
+
+    /** A copy saved with its chunk comes back without its core knowing it: drop it. */
+    private fun onJoin(event: EntityJoinLevelEvent) {
+        if (event.loadedFromDisk() && isDisplay(event.entity)) event.isCanceled = true
+    }
+
+    private fun onBattle(event: BattleStartedEvent.Pre) {
+        if (event.battle.actors.any { actor -> actor.pokemonList.any { isDisplay(it.entity) } }) event.cancel()
+    }
+}