ci(release): publish versioned artifacts

plugins/velocity/README.md

@@ -2,14 +2,24 @@
 
 The plugin checks every online-mode Java login against the account-manager API. It fails closed: unavailable, unauthorized, stale, replayed, malformed, and unknown requests are denied.
 
-## Build
+## Download or build
+
+Versioned JARs are attached to public releases at `https://git.garvis.dev/dmg/minecraft-account-manager/releases`.
+
+To build a development JAR locally:
 
 ```bash
 cd plugins/velocity
 ./gradlew clean test shadowJar
 ```
 
-Copy `build/libs/minecraft-account-manager-velocity-0.1.0.jar` to Velocity's `plugins/` directory and start Velocity once to create `plugins/minecraft-account-manager/config.properties`.
+To embed a release version in both the plugin metadata and filename:
+
+```bash
+./gradlew clean test shadowJar -PreleaseVersion=1.0.0
+```
+
+Copy `build/libs/minecraft-account-manager-velocity-VERSION.jar` to Velocity's `plugins/` directory and start Velocity once to create `plugins/minecraft-account-manager/config.properties`.
 
 ## Provision a credential
 

plugins/velocity/build.gradle.kts

@@ -4,7 +4,9 @@ plugins {
 }
 
 group = "games.dmg"
-version = "0.1.0"
+version = providers.gradleProperty("releaseVersion")
+    .orElse("0.1.0-SNAPSHOT")
+    .get()
 
 repositories {
     mavenCentral()
@@ -24,6 +26,38 @@ java {
     toolchain.languageVersion.set(JavaLanguageVersion.of(17))
 }
 
+val generatedVersionDirectory = layout.buildDirectory.dir("generated/sources/version/java/main")
+val generateVersionSource = tasks.register("generateVersionSource") {
+    val pluginVersion = providers.provider { project.version.toString() }
+    inputs.property("pluginVersion", pluginVersion)
+    outputs.dir(generatedVersionDirectory)
+
+    doLast {
+        val output = generatedVersionDirectory.get()
+            .file("games/dmg/accountmanager/BuildMetadata.java")
+            .asFile
+        output.parentFile.mkdirs()
+        output.writeText(
+            """package games.dmg.accountmanager;
+
+public final class BuildMetadata {
+    public static final String VERSION = "${pluginVersion.get()}";
+
+    private BuildMetadata() {}
+}
+"""
+        )
+    }
+}
+
+sourceSets.main {
+    java.srcDir(generatedVersionDirectory)
+}
+
+tasks.compileJava {
+    dependsOn(generateVersionSource)
+}
+
 tasks.test {
     useJUnitPlatform()
 }

plugins/velocity/src/main/java/games/dmg/accountmanager/MinecraftAccountManagerPlugin.java

@@ -16,7 +16,7 @@ import org.slf4j.Logger;
 @Plugin(
     id = "minecraft-account-manager",
     name = "Minecraft Account Manager",
-    version = "0.1.0",
+    version = BuildMetadata.VERSION,
     description = "Fail-closed admission checks for registered Java accounts"
 )
 public final class MinecraftAccountManagerPlugin {