fix: reject broken configs and improve accuracy feedback with isolated agent state

modelhub_submmit_api/poll_runner.py

@@ -234,7 +234,9 @@ def build_parser() -> argparse.ArgumentParser:
     parser.add_argument("--post-cycle-cooldown-seconds", type=int, default=2, help="Short sleep after a successful cycle")
     parser.add_argument("--max-cycles", type=int, default=0, help="Optional hard stop after N cycles; 0 means run until quota is reached")
     parser.add_argument("--print-stats", action="store_true", help="Load outcomes, sync, print stats report, and exit")
-    parser.add_argument("--disable-queue-cleanup", action="store_true", help=argparse.SUPPRESS)
+    parser.add_argument("--disable-queue-cleanup", action="store_true",
+                        default=os.getenv("MODELHUB_COEXISTENCE_MODE", "1") != "0",
+                        help=argparse.SUPPRESS)
     parser.add_argument(
         "--queue-cleanup-interval-cycles",
         type=int,
@@ -702,6 +704,11 @@ def run_poll_loop(
     STATS_PRINT_INTERVAL = 10
 
     log(f"[poll] version={AGENT_VERSION} poll_run_dir={poll_run_dir}")
+    log(
+        f"[coexistence] state_branch={base_args.state_sync_branch} "
+        f"queue_cancellation={'disabled' if base_args.disable_queue_cleanup else 'enabled'} "
+        "submission_preflight=enabled"
+    )
     log(
         "[state-retention] mode=decision_state_only full_archive=disabled "
         f"recent_outcomes={DEFAULT_RECENT_OUTCOME_LIMIT} "