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/fabric/build.gradle

@@ -0,0 +1,28 @@
+plugins { id 'fabric-loom' version '1.8.13' }
+def mc = providers.gradleProperty('mcVersion').getOrElse('1.21.1')
+if (!(mc in ['1.20.1', '1.21.1'])) throw new GradleException('Use the modern build for 26.x')
+def targetJava = mc == '1.20.1' ? 17 : 21
+loom { mixin { defaultRefmapName = 'scopenet.refmap.json' } }
+if (providers.gradleProperty('verifyMixins').isPresent()) {
+    loom { runs { server { vmArg '-Dscopenet.verifyMixins=true' } } }
+}
+java.sourceCompatibility = JavaVersion.toVersion(targetJava)
+java.targetCompatibility = JavaVersion.toVersion(targetJava)
+dependencies {
+    minecraft "com.mojang:minecraft:${mc}"
+    mappings loom.officialMojangMappings()
+    modImplementation 'net.fabricmc:fabric-loader:0.16.10'
+    implementation project(':common')
+}
+sourceSets.main.java.srcDirs += ['../minecraft/src/main/java', "../minecraft/src/${mc}/java"]
+sourceSets.main.resources.srcDirs += ['../minecraft/src/main/resources']
+apply from: '../minecraft/build-info.gradle'
+processResources {
+    inputs.properties(version: project.version, mc: mc, java: targetJava)
+    filesMatching('fabric.mod.json') { expand(version: project.version, mc: mc, java: targetJava) }
+}
+jar {
+    archiveBaseName = "scopenet-fabric-${mc}"
+    from project(':common').sourceSets.main.output
+}
+base.archivesName = "scopenet-fabric-${mc}"

integrations/fabric/modern.gradle

@@ -0,0 +1,22 @@
+plugins { id 'net.fabricmc.fabric-loom' version '1.17.17' }
+def mc = providers.gradleProperty('mcVersion').get()
+if (providers.gradleProperty('verifyMixins').isPresent()) {
+    loom { runs { server { vmArg '-Dscopenet.verifyMixins=true' } } }
+}
+java.sourceCompatibility = JavaVersion.VERSION_25
+java.targetCompatibility = JavaVersion.VERSION_25
+dependencies {
+    minecraft "com.mojang:minecraft:${mc}"
+    implementation 'net.fabricmc:fabric-loader:0.19.5'
+    implementation project(':common')
+}
+sourceSets.main.java.srcDirs += ['../minecraft/src/main/java', '../minecraft/src/26/java']
+sourceSets.main.resources.srcDirs += ['../minecraft/src/main/resources']
+apply from: '../minecraft/build-info.gradle'
+processResources {
+    inputs.properties(version: project.version, mc: mc)
+    filesMatching('fabric.mod.json') { expand(version: project.version, mc: mc, java: 25) }
+    filesMatching('scopenet.mixins.json') { filter { line -> line.contains('"refmap"') ? null : line } }
+}
+base.archivesName = "scopenet-fabric-${mc}"
+jar { from project(':common').sourceSets.main.output }

integrations/fabric/src/main/java/net/scopenet/fabric/ScopenetFabric.java

@@ -0,0 +1,11 @@
+package net.scopenet.fabric;
+
+import net.fabricmc.api.DedicatedServerModInitializer;
+
+/** Server-only; lifecycle and admission hooks are shared mixins. */
+public final class ScopenetFabric implements DedicatedServerModInitializer {
+    @Override public void onInitializeServer() {
+        if (Boolean.getBoolean("scopenet.verifyMixins"))
+            org.spongepowered.asm.mixin.MixinEnvironment.getCurrentEnvironment().audit();
+    }
+}

integrations/fabric/src/main/resources/fabric.mod.json

@@ -0,0 +1,10 @@
+{
+  "schemaVersion": 1,
+  "id": "scopenet",
+  "version": "${version}",
+  "name": "SCOPENET",
+  "environment": "server",
+  "entrypoints": { "server": ["net.scopenet.fabric.ScopenetFabric"] },
+  "mixins": ["scopenet.mixins.json"],
+  "depends": { "fabricloader": ">=0.16.10", "minecraft": "${mc}", "java": ">=${java}" }
+}