Fabric 1.20.1: server features (commands, LuckPerms, Placeholder API, economy API, client link) and client mod (HUD, editor, shop and market windows); Paper client link; docs and examples

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DjMbLQujBHunCCu5GpsHaT

integrations/fabric/build.gradle

@@ -8,12 +8,19 @@ if (providers.gradleProperty('verifyMixins').isPresent()) {
 }
 java.sourceCompatibility = JavaVersion.toVersion(targetJava)
 java.targetCompatibility = JavaVersion.toVersion(targetJava)
+def features = mc == '1.20.1'   // commands, permissions, economy, client link: Fabric API based, 1.20.1 only for now
 dependencies {
     minecraft "com.mojang:minecraft:${mc}"
     mappings loom.officialMojangMappings()
     modImplementation 'net.fabricmc:fabric-loader:0.16.10'
     implementation project(':common')
+    if (features) {
+        modImplementation 'net.fabricmc.fabric-api:fabric-api:0.92.2+1.20.1'
+        // Optional at runtime: present only when the LuckPerms mod is installed.
+        compileOnly 'net.luckperms:api:5.4'
+    }
 }
+if (features) sourceSets.main.java.srcDirs += ['src/mc1.20.1/java']
 sourceSets.main.java.srcDirs += ['../minecraft/src/main/java', "../minecraft/src/${mc}/java"]
 sourceSets.main.resources.srcDirs += ['../minecraft/src/main/resources']
 apply from: '../minecraft/build-info.gradle'