News informational-only: gate sentiment bonus/penalty off by default

Add NewsConfig.sentiment_affects_signals (default False), gating the +5
aligned-sentiment confidence bonus and the 10-pt news_conflict penalty.
With event_risk_caps_signals already False, live decisions are now pure
technical, matching the backtester (use_news=False). Warnings and the
sentiment display are unchanged. Adds a gating regression test.

Claude-Session: https://claude.ai/code/session_01FMaaPdrrrQuh1VvGQH1icN

signal_aggregator.py

@@ -1079,7 +1079,7 @@ class SignalAggregator:
                 mtf_avg = sum(all_scores) / len(all_scores)
                 score = score * 0.6 + mtf_avg * 0.4
 
-        if abs(report.news_sentiment) > 0.2:
+        if self.config.news.sentiment_affects_signals and abs(report.news_sentiment) > 0.2:
             if (report.news_sentiment > 0 and score > 0) or \
                (report.news_sentiment < 0 and score < 0):
                 confidence += 5
@@ -1129,7 +1129,8 @@ class SignalAggregator:
             if (report.news_sentiment > 0 and score < -10) or \
                (report.news_sentiment < 0 and score > 10):
                 report.warnings.append("News sentiment CONFLICTS with technical signal")
-                penalties.append(("news_conflict", 10))
+                if self.config.news.sentiment_affects_signals:
+                    penalties.append(("news_conflict", 10))
 
         if report.event_risk == "caution":
             report.warnings.append(f"Upcoming event: {report.event_description}")