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/simple-voice-chat.pw.toml

@@ -1,13 +1,13 @@
 name = "Simple Voice Chat"
-filename = "voicechat-fabric-2.6.21+26.2.jar"
+filename = "voicechat-fabric-2.6.23+26.3.jar"
 side = "both"
 
 [download]
-url = "https://cdn.modrinth.com/data/9eGKb6K1/versions/3SOh5iiX/voicechat-fabric-2.6.21%2B26.2.jar"
+url = "https://cdn.modrinth.com/data/9eGKb6K1/versions/3fRw6NfP/voicechat-fabric-2.6.23%2B26.3.jar"
 hash-format = "sha512"
-hash = "0308b2e18a05913faaf461530a475d2f5debbfb4d0a46107b512ce51166ceb6cfdbea468f7e21444a3e005655e51729c3764266f81c59b6228629b4866d16b28"
+hash = "fd62ca0b4048ab855e7f2436ecdf6c7301e546946afe2d7a3dfa3fb7c180636cbd971c0e9c5e62be4a86d67bbed54fa62ab4d4680c47ea0b366e49b9202ff42a"
 
 [update]
 [update.modrinth]
 mod-id = "9eGKb6K1"
-version = "3SOh5iiX"
+version = "3fRw6NfP"