IOB Deadlock Fixes

1.2.0 — IoB Variant Loader ownerless follow-goal guard

Fixes a server crash while ticking a tamed dragon whose owner could not be resolved:

java.lang.NullPointerException: Cannot invoke "net.minecraft.world.entity.Entity.m_20185_()" because "p_24961_" is null
  at net.minecraft.world.entity.ai.control.LookControl.m_24960_
  at nordmods.iobvariantloader.util.alt_navigation.AltFollowGoal.m_8037_

What changed

• The optional IoB Variant Loader guard is now included in the single published jar. It cancels the alternate follow goal's canUse() and skips its tick() when the dragon has no resolvable owner, so Minecraft's LookControl/navigation never receive a null entity.
• Compile target updated from IoB Variant Loader 2.6.4 to 2.7.0, bytecode-verified against the live 2.7.0 artifact (fields tamable/navigation, methods m_8036_()Z/m_8037_()V all confirmed).
• Version 1.1.2 → 1.2.0.

Compatibility

• Minecraft 1.18.2, Forge 40.x+, Java 17.
• Requires Isle of Berk 1.2.x. IoB Variant Loader is optional — the adapter mixin is soft (required=false) and the dependency is declared optional, so the jar is inert and safe if Variant Loader is not installed.
• Both sides (server-side fix; a client copy is harmless).

The existing ADragonBase.isWaterBelow() worldgen-deadlock guard is unchanged and still included.