grand-exchange-live: protocol layer, taskset, config, widened reference gate

The stepped engine becomes a runnable taskset. protocol.py is both the
render/parse boundary and the security boundary: TurnView carries the live
Market, so view.market.items[i].prices is the whole held-out series and a
foresight policy reading it earned +9.4% on the oracle. The renderer emits only
observed ticks, the trace carries plain scalars, and a sentinel scan of every
rendered turn fails if either reopens. House rule 1 had no other enforcement.

Replies are a delta sheet and parsing never raises — NaN, Infinity, 1e309 and
20k-deep nesting all resolve to a hold, because the one-shot form has already
shown what a real model sends when it gives up.

LiveExchangeEnv.run drives the engine host-side with the harness left null. Two
things learned the hard way and worth keeping: a terminated Segment mid-window
holds the remaining looks instead of raising, and rewards are recorded INSIDE
the interaction, before close. Recording after close writes the traces correctly
and leaves every eval.log line reading reward=0.000 — the canonical verifiers
reference does it after the block; do not copy it there.

The reference-family gate is widened from four named rungs to the whole 8x8
(requote_band, idle_share) family: no member may out-earn the shipped reference
by more than 1.02x, and any that does must still score >= 0.90. That is the check
that caught the first draft's fake 0.152 gap, now shipped rather than remembered.

Also guards `clean` on the reference being profitable, here and in the one-shot
form. Against a reference that lost money the bar is negative, so doing nothing
cleared it and inaction collected a quarter of the reward. Unreachable while
viable_market admits only profitable references; one relaxed filter from
reachable, and exactly the floor house rule 3 forbids. Probe values unchanged.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

environments/grand_exchange/grand_exchange/book.py

@@ -412,9 +412,17 @@ class Outcome:
         one-unit order that never fills has identical realised profit and lost 0.146 of
         total reward. The bar is now TARGET_SHARE of the reference on the money AND on the
         return that money made, which is a run that was worth doing however it got there.
+
+        Guarded on the reference being profitable at all. Against a reference that LOST
+        money the bar is negative, so doing nothing clears it and inaction collects this
+        whole component — the floor violation house rule 3 exists to forbid. Unreachable
+        while `viable_market` only admits profitable references; one relaxed filter from
+        reachable. `grand_exchange_live.reward.score` carries the same guard.
         """
         return (
-            self.fills.realised >= TARGET_SHARE * self.reference.realised
+            self.reference.realised > 0
+            and self.reference.roc > 0
+            and self.fills.realised >= TARGET_SHARE * self.reference.realised
             and self.fills.roc >= TARGET_SHARE * self.reference.roc
         )