Only kinds below their target share are generated and run; one-controller flock guard

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

harness/trainset.py

@@ -279,7 +279,7 @@ def run_balanced(part, parts, deadline):
         if blocked:
             print("kinds skipped (low acceptance):", sorted(blocked), flush=True)
         waiting = {k for k, n in backlog_by_kind().items() if n > BAL_KIND_BACKLOG}
-        allowed = set(mix.TYPE_SHARE) - blocked - waiting
+        allowed = (set(mix.TYPE_SHARE) - blocked - waiting) & mix.below_target(counts)   # only kinds below their share
         if not allowed:
             time.sleep(120)     # every kind has a backlog: the trajectories are the slower side
             continue