ci: add plugin build and release pipeline

design/user-stories/us-007-build-and-release-plugin.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-007: Build and release the plugin"
 description: Give maintainers repeatable Java builds, automated verification, and versioned Gitea releases.
-status: backlog
+status: done
 ---
 
 # US-007: Build and release the plugin
@@ -11,14 +11,14 @@ As a **plugin maintainer**, I want automated builds and releases so that tested,
 
 ## Acceptance criteria
 
-- [ ] The Gradle project compiles with Java 17 against Spigot API 26.2.
-- [ ] Automated tests run as part of the Gradle `check` lifecycle.
-- [ ] Pushes and pull requests build and test the plugin in Gitea Actions.
-- [ ] Pull requests validate conventional commit messages.
-- [ ] CI stores a development JAR as a workflow artifact.
-- [ ] Main-branch conventional commits drive semantic versioning.
-- [ ] A successful release builds a versioned JAR and attaches it to the corresponding Gitea release.
-- [ ] Build, installation, command, permission, configuration, and release procedures are documented.
+- [x] The Gradle project compiles with Java 17 against Spigot API 26.2.
+- [x] Automated tests run as part of the Gradle `check` lifecycle.
+- [x] Pushes and pull requests build and test the plugin in Gitea Actions.
+- [x] Pull requests validate conventional commit messages.
+- [x] CI stores a development JAR as a workflow artifact.
+- [x] Main-branch conventional commits drive semantic versioning.
+- [x] A successful release builds a versioned JAR and attaches it to the corresponding Gitea release.
+- [x] Build, installation, command, permission, configuration, and release procedures are documented.
 
 ## Related