feat(strategy): skip markets with extreme priors (< 0.08 or > 0.92)

Markets where Polymarket consensus is near-certain leave no room for our
signals to generate MIN_EDGE=0.10 — evaluating them wastes GNews quota and
produces noise. Filter them out early with a clear log reason.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bot/strategy/bayesian.py

@@ -129,6 +129,23 @@ class BayesianStrategy:
         # The market already aggregates information from many traders;
         # our signals update from that informed baseline, not from 0.5.
         prior = max(0.05, min(0.95, market.yes_price))
+
+        # Skip markets where the crowd has already reached near-certainty.
+        # Below 0.08 or above 0.92 there is not enough room for our signals
+        # to generate MIN_EDGE — any trade would be fighting near-certain consensus.
+        if market.yes_price < 0.08:
+            log.info(
+                "SKIP  %-50s | cat=%-12s | prior=%.3f | reason=prior too low, market already certain",
+                market.question[:50], category, market.yes_price,
+            )
+            return None
+        if market.yes_price > 0.92:
+            log.info(
+                "SKIP  %-50s | cat=%-12s | prior=%.3f | reason=prior too high, market already certain",
+                market.question[:50], category, market.yes_price,
+            )
+            return None
+
         sources: list[str] = [f"Prior=poly({prior:.3f})"]
         adjustments: list[float] = []