port to Minecraft 26.3

Source changes for 26.3 API breakage:
- block codec system removed upstream (Block has no MapCodec/codec()/
  simpleCodec anymore): drop CODEC + codec() from AmethystCauldronBlock
  and GravityCrystalBlock
- Entity.hurtMarked -> Entity.syncVelocity (pure rename, still public)
- LivingEntity.drop() now takes a Prediction; our drops are server-
  initiated and unpredicted, so they pass SERVER_ONLY
- canSimulateMovement() became final; the ravager/hoglin mount mixins
  now override getMoveSimulationType() and return
  AUTHORITATIVE_SIDE_AND_SERVER, which is the same "server always
  simulates" semantics the old !isClientSide branch had
- loot number providers split into providers.number.{ints,floats} and
  became Holder-based: UniformGenerator.between(1f,3f) ->
  ContextIntProviders.between(1,3)
- BonemealableBlock methods take a BonemealSource (INTERACTION here)
- clockManager().getTotalTicks(c) ->
  clockManager().getInstance(c).totalTicks()
- EnderMan -> Enderman (capitalisation only)

Build: MC 26.3, loader 0.19.5, fabric-api 0.160.5+26.3, loom 1.18.1,
gradle wrapper 9.6.0 -> 9.7.1 (loom 1.18.x requires Gradle >= 9.7).
Polymer is 0.18.0+26.3-rc-1: upstream has not published a 26.3-final
build yet, that rc build is the only one on the 26.3 line.

server-deploy: pack.toml -> 26.3 / loader 0.19.5; fabric-api, polymer
and simple-voice-chat are the only pack mods with 26.3 builds and were
updated (index hashes regenerated). The remaining third-party mods have
no 26.3 release yet and are deliberately left untouched. Dockerfile now
pins the justbackup and fabric-carpet forks to their 26.3 branches
instead of silently building whatever the default branch holds.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

server-deploy/pack/mods/fabric-api.pw.toml

@@ -1,13 +1,13 @@
 name = "Fabric API"
-filename = "fabric-api-0.155.2+26.2.jar"
+filename = "fabric-api-0.160.5+26.3.jar"
 side = "both"
 
 [download]
-url = "https://cdn.modrinth.com/data/P7dR8mSH/versions/lVXlbH4w/fabric-api-0.155.2%2B26.2.jar"
+url = "https://cdn.modrinth.com/data/P7dR8mSH/versions/oCYG2H4L/fabric-api-0.160.5%2B26.3.jar"
 hash-format = "sha512"
-hash = "cc56984378a27c5bcd56374d6ffbb27a45c6bf3355add2ac6be9817ccac5854362249bf9d0147eb271a70fda2716129204e240d53c9aa876a2a7861f4c7f880f"
+hash = "494378477dd9571f49c27cc1eaee3f78f140b9d8bd860c757f453bee198fd5b8a9eee444069c595b0fb6f8cb6bc86d51ccddbcec8d782fd46ef2fb1d9ac22f16"
 
 [update]
 [update.modrinth]
 mod-id = "P7dR8mSH"
-version = "lVXlbH4w"
+version = "oCYG2H4L"