refactor(build): decouple per-module versioning

Each module uses its own version property instead of a shared
artefactVersion, so changes to one module no longer force a
version bump across all modules. CI now supports per-module
release tags with the format <module>/v<version>.

identity-generator/build.gradle.kts

@@ -29,7 +29,9 @@ plugins {
     id("signing")
 }
 
-val artefactVersion: String by project
+val identityGeneratorVersion: String by project
+
+version = identityGeneratorVersion
 val projectUrl: String by project
 val projectGithubUrl: String by project
 val licenseName: String by project
@@ -70,7 +72,7 @@ publishing {
         create<MavenPublication>("identityGenerator") {
             groupId = group.toString()
             artifactId = "identity-generator"
-            version = artefactVersion
+            version = identityGeneratorVersion
 
             pom {
                 name = "OnixByte Identity Generator"