Build for Minecraft 26.1, 26.2 and 26.3

Adds the three drops as Stonecutter versions (26.1's jar also accepts
its hotfixes). loom-back-compat already picks the plain Loom for 26.x;
the testmod's remap configurations are only created where there's
something to remap, and the foojay resolver downloads the Java 25
toolchain these versions need.

- 26.3 renamed PoseStack.mulPose(Quaternionfc) to rotate.
- The testmod follows Fabric API's renames: ClientCommands (26.1),
  getClientLevel (26.1) and getConnection (26.2) for waiting on chunks.
- 26.2 replaced Options.hideGui with the HUD's toggle, so the gametest
  toggles it through a helper.

The screenshot gametest passes on 26.1, 26.2 and 26.3, and the bent
limbs match 1.21.11's.

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

settings.gradle.kts

@@ -9,6 +9,8 @@ pluginManagement {
 }
 
 plugins {
+    // Downloads the Java toolchain a version needs (Java 25 for 26.1+) when it isn't installed.
+    id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"
     id("dev.kikugie.stonecutter") version "0.9.8"
     // Picks the right Loom variant per Minecraft version (remapping for 1.21.x, plain for 26.1+).
     id("dev.kikugie.loom-back-compat") version "0.4.2"
@@ -17,7 +19,7 @@ plugins {
 stonecutter {
     create(rootProject) {
         // Same range as Saturn Client. Per-version dependencies live in stonecutter.properties.toml.
-        versions("1.21.4", "1.21.5", "1.21.6", "1.21.7", "1.21.8", "1.21.9", "1.21.10", "1.21.11")
+        versions("1.21.4", "1.21.5", "1.21.6", "1.21.7", "1.21.8", "1.21.9", "1.21.10", "1.21.11", "26.1", "26.2", "26.3")
         vcsVersion = "1.21.11"
     }
 }