fix: wait for concurrent job to finish instead of returning permanent blocked error (FAR-61)

When multiple tasks are assigned simultaneously, only one K8s job can run
at a time (shared PVC/session guard). Previously, all other tasks received
k8s_concurrent_run_blocked immediately and stayed blocked forever.

Now the guard retries once: wait for all blocking jobs to complete via
waitForJobCompletion, then re-check before proceeding to create a new job.
If the re-check still shows a running job, the error is returned as before.

The agentCreationMutex already serializes guard-check + job-create, so
tasks naturally queue up and execute one at a time without concurrent jobs.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "paperclip-adapter-opencode-k8s",
-  "version": "0.1.18",
+  "version": "0.1.23",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "paperclip-adapter-opencode-k8s",
-      "version": "0.1.18",
+      "version": "0.1.23",
       "license": "MIT",
       "dependencies": {
         "@kubernetes/client-node": "^1.0.0",