Move gravity direction system to Anthology

Gravity API, mixins, projectile compat, inverted effect, gravity sync and
/gravity now live in the Anthology library. Antarchy registers the Underside
region, antiwater, stale-inversion cleanup and portal gun camera roll through
GravityHooks, and depends on the local Anthology jar in anthology_jars/.

common-1.21.1/src/main/resources/antarchy-common.mixins.json

@@ -72,49 +72,13 @@
                    "SquidzookaMultishotMixin",
                    "TigerEyeCamouflageMixin",
                    "TigerEyeVisibilityMixin",
-                   "gravity.AbstractArrowGravityMixin",
-                   "gravity.BehaviorUtilsGravityMixin",
-                   "gravity.BucketItemGravityMixin",
-                   "gravity.BubbleColumnGravityMixin",
                    "gravity.ChunkMapAccessor",
-                   "gravity.CrossbowItemGravityMixin",
-                   "gravity.DirectionFacingMixin",
-                   "gravity.EntityCollisionContextMixin",
-                   "gravity.EntityGravityFrameMixin",
-                   "gravity.EntityGravityMixin",
-                   "gravity.EntityMoveMixin",
-                   "gravity.EntityProjectileGravityMixin",
-                   "gravity.ExplosionGravityMixin",
                    "gravity.FallingBlockEntityBlockDataMixin",
-                   "gravity.FireworkRocketGravityMixin",
-                   "gravity.GroundPathNavigationMixin",
-                   "gravity.LivingEntityMixin",
-                   "gravity.MeleeAttackGoalGravityMixin",
-                   "gravity.MoveControlGravityMixin",
-                   "gravity.MobHurtMixin",
-                   "gravity.PathNavigationAccessor",
                    "gravity.PlayerAttackMixin",
-                   "gravity.PlayerGravityMixin",
-                   "gravity.PlayerPoseFitMixin",
-                   "gravity.PlayerSneakMixin",
-                   "gravity.RandomStrollGoalGravityMixin",
-                   "gravity.ProjectileGravityMixin",
                    "gravity.ServerChunkCacheAccessor",
                    "gravity.ServerEntityAccessor",
-                   "gravity.ServerGamePacketListenerMixin",
-                   "gravity.ServerPlayerGravityMixin",
-                   "gravity.ThrowableProjectileGravityMixin",
                    "gravity.TrackedEntityAccessor",
                    "compat.biolith.MultiNoiseBiomeSourceNullGuardMixin",
-                   "compat.scguns.ScgunsProjectileEntityAccessMixin",
-                   "compat.scguns.ScgunsProjectileEntityGravityMixin",
-                   "compat.scguns.ScgunsArrowGravityMixin",
-                   "compat.irons_spellbooks.IronsSpellbooksProjectileGravityMixin",
-                   "compat.ars_nouveau.ArsNouveauProjectileGravityMixin",
-                   "compat.alexscaves.AlexsCavesCandyCaneHookMixin",
-                   "compat.alexscaves.AlexsCavesWaterBoltMixin",
-                   "compat.alexscaves.AlexsCavesTephraMixin",
-                   "compat.alexscaves.AlexsCavesDepthChargeMixin",
                    "multipart.EntityMultipartLifecycleMixin",
                    "time.EntityDeltaMovementTimeDilationMixin",
                    "time.EntityMoveTimeDilationMixin",
@@ -191,9 +155,6 @@
                    "client.TigerEyeNameTagHideMixin",
                    "client.TemporalContractionLivingRendererMixin",
                    "client.WolfRendererGrimMixin",
-                   "gravity.client.CameraGravityMixin",
-                   "gravity.client.ClientPacketListenerGravityMixin",
-                   "gravity.client.EntityRenderDispatcherGravityMixin",
                    "gravity.client.FallingBlockRendererBlockEntityMixin",
                    "time.LivingEntityRendererAnimationTimeDilationMixin",
                    "time.ParticleTimeDilationMixin",