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]>

README.md

@@ -1,3 +1,58 @@
-# emote
+# emotes
 
-A powerful emote library for Saturn Client, with bending
+A player emote library for Saturn Client, with limb bending.
+
+## Layout
+
+- `core/`: Minecraft-independent animation model (`Bone`, `BoneTransform`, `Pose`, `Animation`,
+  `AnimationPlayer`). Plain Java 21 with JUnit tests. Published as `org.saturnclient:emotes-core`.
+- `src/main/`: the Fabric mod that puts poses on player models. It's built once per Minecraft
+  version with [Stonecutter](https://stonecutter.kikugie.dev/) and published as
+  `org.saturnclient:emotes-fabric:<version>+<mc>`, with `core` bundled inside the jar.
+- `src/testmod/`: a dev-only tester mod that is never published. It adds `/emotes play <name>`,
+  `/emotes stop` and `/emotes info`. Press F5 to see yourself.
+
+Supported versions: 1.21.4 to 1.21.11, the same range as Saturn Client. Each version's Fabric API
+version is set in `stonecutter.properties.toml`. The code uses Mojang mappings.
+
+## How it hooks in
+
+1. `LivingEntityRendererMixin` samples the entity's current pose into its render state (players only).
+2. `HumanoidModelMixin` applies that pose at the end of `HumanoidModel.setupAnim`. `PlayerModel`
+   and the armor layers both go through this method, so armor follows the pose.
+
+Both hook points exist unchanged in every supported version. Version-specific code goes behind
+Stonecutter comments:
+
+```java
+//? if >=1.21.9 {
+import net.minecraft.client.renderer.entity.state.AvatarRenderState;
+//?} else
+/*import net.minecraft.client.renderer.entity.state.PlayerRenderState;*/
+```
+
+Bending (`BoneTransform.bend` / `bendAxis`) is part of the model but isn't rendered yet.
+
+## Commands
+
+```sh
+./gradlew :core:test                      # core unit tests
+./gradlew :1.21.11:runTestmodClient       # launch the game with the tester (run dir: ./run)
+./gradlew :1.21.4:compileTestmodJava      # quick compile check for one version
+./gradlew buildAll                        # every version's jar → build/libs/<version>/
+GITEA_TOKEN=... ./gradlew publish         # publish core + every version to Gitea
+```
+
+The active version is set in `stonecutter.gradle.kts` (`stonecutter active "..."`), and it's the
+version whose code is uncommented in `src/`. Switch versions with the Stonecutter IntelliJ plugin
+or the `Set active project to <v>` Gradle task. Run `Reset active project` before committing, so
+the tree is committed with `vcsVersion` (1.21.11) active.
+
+Loom 1.18 needs a Java 25 JVM to run Gradle, so the build is pinned to Loom 1.17 until the
+toolchain moves. Minecraft 26.x will need that upgrade.
+
+## Publishing
+
+Artifacts go to the `saturnclientmc` organization's Maven registry:
+`https://git.selimaj.dev/api/packages/saturnclientmc/maven`. Use a token with `package:write`, set
+as `GITEA_TOKEN` or `-PgiteaToken=...`.