ALEC-296: driverInit returns error Response on InterruptedException

Addresses Copilot review feedback on PR #154. Without this,
reEvaluateAllOpenAlarms() (and the existing engine-config save paths)
could report HTTP 200 even when the driver init was interrupted before
the engine came back up — masking failures from the caller.

(The companion test fix for the missing re-evaluate confirm-cancel
no-op test was already pushed by Copilot Autofix as 19bc094.)

Author: joseanesONMS

features/ui/src/main/java/org/opennms/alec/rest/EngineRestImpl.java

@@ -203,8 +203,9 @@ private Response driverInit(Driver driver) {
         try {
             future.get();
         } catch (InterruptedException e) {
-            LOG.error("Engine creation failed", e.getCause());
+            LOG.error("Engine creation interrupted", e);
             Thread.currentThread().interrupt();
+            return ALECRestUtils.somethingWentWrong(e);
         } catch (ExecutionException e) {
             LOG.error("Engine creation failed", e.getCause());
             return ALECRestUtils.somethingWentWrong(e);