chore: move the JDT LS components out of plugins/ (#1292)

java-usages, kotlin-bridge and the patched Lombok agent are JDT LS bundles and a Java agent embedded into the app, not OpenIDEA plugins. Move them to java/ so plugins/ holds only plugins, and update the paths that embed or mention them.

Also fix the stale build path in the hello fixture and the contributor guide's layout (there is no templates/ directory; starter templates live in the openidea-plugin CLI).

crates/ide-sdk/src/java.rs

@@ -1128,7 +1128,7 @@ mod tests {
 /// The same jar supplies the JDT command and the private Maven output redirector.
 pub fn kotlin_bridge_bundle(data_dir: &Path) -> Option<PathBuf> {
     let extension = data_dir.join("kotlin-bridge-1.0.0.jar");
-    let bytes = include_bytes!("../../../plugins/kotlin-bridge/openidea-kotlin-bridge.jar");
+    let bytes = include_bytes!("../../../java/kotlin-bridge/openidea-kotlin-bridge.jar");
     if std::fs::read(&extension).is_ok_and(|old| old == bytes) {
         return Some(extension);
     }
@@ -1171,7 +1171,7 @@ mod kotlin_bridge_bundle_tests {
 /// Installs the app-owned JDT LS command bundle, falling back to ordinary LSP on IO failure.
 pub fn usages_bundle(data_dir: &Path) -> Option<PathBuf> {
     let extension = data_dir.join("java-usages-1.3.0.jar");
-    let bytes = include_bytes!("../../../plugins/java-usages/openidea-java-usages.jar");
+    let bytes = include_bytes!("../../../java/java-usages/openidea-java-usages.jar");
     if std::fs::read(&extension).is_ok_and(|old| old == bytes) {
         clean_usages_bundles(data_dir, &extension);
         return Some(extension);
@@ -1256,10 +1256,7 @@ mod usages_bundle_tests {
     fn installs_the_exact_bundle_and_reuses_it() {
         let dir = tempfile::tempdir().unwrap();
         let jar = super::usages_bundle(dir.path()).unwrap();
-        assert_eq!(
-            std::fs::read(&jar).unwrap(),
-            include_bytes!("../../../plugins/java-usages/openidea-java-usages.jar")
-        );
+        assert_eq!(std::fs::read(&jar).unwrap(), include_bytes!("../../../java/java-usages/openidea-java-usages.jar"));
         assert_eq!(super::usages_bundle(dir.path()), Some(jar));
         assert_eq!(std::fs::read_dir(dir.path()).unwrap().count(), 1);
     }