Scaffold the emote library with a Stonecutter Fabric mod and tester

- core/: Minecraft-independent animation model (Bone, BoneTransform with
  bend fields, Pose, Animation, AnimationPlayer) with JUnit tests.
- src/main: Fabric mod built for 1.21.4-1.21.11 with Stonecutter on
  Mojang mappings. Samples each player's pose into its render state and
  applies it at the end of HumanoidModel.setupAnim (armor follows too).
- src/testmod: dev-only tester with /emotes play|stop|info and a mixin
  audit on startup.
- Publishing to the saturnclientmc Gitea Maven registry as
  org.saturnclient:emotes-core and emotes-fabric:<v>+<mc>.

Loom is pinned to 1.17 because 1.18 needs a Java 25 JVM.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

stonecutter.gradle.kts

@@ -0,0 +1,23 @@
+plugins {
+    id("dev.kikugie.stonecutter")
+}
+
+stonecutter active "1.21.11"
+
+// See https://stonecutter.kikugie.dev/wiki/config/params
+stonecutter parameters {
+    swaps["mod_version"] = "\"${property("mod.version")}\";"
+    swaps["minecraft"] = "\"${node.metadata.version}\";"
+
+    replacements {
+        string(current.parsed >= "1.21.11") {
+            replace("ResourceLocation", "Identifier")
+        }
+    }
+}
+
+// Builds and collects every version's jar into build/libs/<mod version>/.
+tasks.register("buildAll") {
+    group = "build"
+    dependsOn(stonecutter.tasks.named("buildAndCollect"))
+}