Add incomplete Minecraft 26.3 port prototype

ports/mc263/build.gradle

@@ -0,0 +1,94 @@
+plugins {
+    id 'java-library'
+    id 'net.neoforged.moddev' version '2.0.148'
+}
+
+group = 'net.dnorberg.rivencraft'
+version = mod_version
+
+base {
+    archivesName = "rivencraft-${minecraft_version}-INCOMPLETE"
+}
+
+java.toolchain.languageVersion = JavaLanguageVersion.of(25)
+
+neoForge {
+    version = project.neo_version
+    runs {
+        client {
+            client()
+            if (project.hasProperty('connectAddress')) {
+                programArgument '--quickPlayMultiplayer'
+                programArgument project.property('connectAddress').toString()
+            }
+            if (project.hasProperty('clientName')) {
+                programArgument '--username'
+                programArgument project.property('clientName').toString()
+                gameDirectory = project.layout.buildDirectory.dir('run-client-' + project.property('clientName')).get().asFile
+            }
+        }
+        server {
+            server()
+            gameDirectory = project.hasProperty('serverRunDir')
+                    ? file(project.property('serverRunDir').toString())
+                    : project.layout.buildDirectory.dir('run-server').get().asFile
+            programArgument '--nogui'
+        }
+    }
+    mods {
+        rivencraft {
+            sourceSet(sourceSets.main)
+        }
+    }
+}
+
+def generateModMetadata = tasks.register('generateModMetadata', ProcessResources) {
+    def replaceProperties = [
+            mod_id: mod_id,
+            mod_name: mod_name,
+            mod_license: mod_license,
+            mod_version: mod_version,
+            neo_version: neo_version,
+            minecraft_version_range: minecraft_version_range,
+    ]
+    inputs.properties replaceProperties
+    expand replaceProperties
+    from 'src/main/templates'
+    into 'build/generated/sources/modMetadata'
+}
+sourceSets.main.resources.srcDir generateModMetadata
+neoForge.ideSyncTask generateModMetadata
+
+tasks.named('processResources', ProcessResources).configure {
+    // Reuse the existing sprite and base model without copying binary assets.
+    from('../../src/main/resources') {
+        include 'assets/rivencraft/textures/item/crystal_shard.png'
+        include 'assets/rivencraft/models/item/crystal_shard.json'
+        include 'assets/rivencraft/textures/item/descriptive_book.png'
+        include 'assets/rivencraft/models/item/descriptive_book.json'
+        include 'assets/rivencraft/textures/item/linking_book.png'
+        include 'assets/rivencraft/models/item/linking_book_bound.json'
+        include 'assets/rivencraft/textures/gui/bookui_cover.png'
+        include 'assets/rivencraft/textures/gui/notebook_pages.png'
+        include 'assets/rivencraft/textures/gui/bookui_pager.png'
+        include 'assets/rivencraft/textures/block/crystal_block.png'
+        include 'assets/rivencraft/models/block/crystal_block.json'
+        include 'assets/rivencraft/blockstates/crystal_block.json'
+        include 'data/rivencraft/loot_table/blocks/crystal_block.json'
+    }
+}
+
+// This partial 26.3 port is not a playable release. An explicitly requested
+// local test JAR can be built with -PallowIncompletePortJar=true, but the
+// default build must never produce a distributable artifact.
+tasks.named('jar').configure {
+    enabled = providers.gradleProperty('allowIncompletePortJar').map(String::toBoolean).getOrElse(false)
+}
+
+tasks.withType(JavaCompile).configureEach {
+    options.encoding = 'UTF-8'
+}
+
+tasks.named('runServer').configure {
+    standardInput = System.in
+}