fix: prevent repeated model GPU submissions

modelhub_submmit_api/README.md

@@ -83,6 +83,10 @@ bash run_poll.sh --dry-run
   7 days, 30 days, and older history (up to 3,000 models) when the recent pool is exhausted.
 - Model verification responses are cached across poll cycles for 15 minutes. Local model/GPU
   failures cool down after 24 hours instead of remaining permanently blocked.
+- Community deduplication is model/GPU-specific: another GPU's adaptation does not block the
+  current GPU. Every actual submission performs a fresh uncached check for its exact GPU.
+- If the community lookup is unavailable, submission is deferred. A platform model-uniqueness
+  rejection permanently excludes only that model/GPU combination from future local retries.
 - Each model can be submitted at most once per GPU.
 - Multiple ModelHub tokens are pooled and used to route submissions to the account with available async capacity.
 - Concurrent submissions reserve account slots locally, and an account-capacity race automatically falls through to another account.
@@ -148,6 +152,7 @@ Persistent local scheduler state is written under `.modelhub_state/`:
 
 - `gpu_strategy.json`: GPU ranks, generation progress, and 50/30/20 accepted counters
 - `account_capacity.json`: learned per-account active-task limits
+- `submission_exclusions.jsonl`: non-retryable model/GPU uniqueness rejections
 
 ## Verification