Complete private authentication, server integrations and activity reporting

Add Fabric/Forge version builds and Paper integration, preserve permanent player identities across renames, harden session authorization, and surface privacy-conscious launcher/server activity in the panel.

integrations/minecraft/build-info.gradle

@@ -0,0 +1,18 @@
+def generated = layout.buildDirectory.dir('generated/scopenet')
+sourceSets.main.java.srcDir generated
+tasks.register('generateBuildInfo') {
+    inputs.property('version', project.version)
+    inputs.property('loader', project.name)
+    outputs.dir generated
+    doLast {
+        def target = generated.get().file('net/scopenet/minecraft/BuildInfo.java').asFile
+        target.parentFile.mkdirs()
+        target.text = """package net.scopenet.minecraft;
+public final class BuildInfo {
+    public static final String VERSION = "${project.version}";
+    public static final String LOADER = "${project.name}";
+}
+"""
+    }
+}
+compileJava.dependsOn generateBuildInfo