signal_log: persist agent panel verdict + per-persona takes to SQLite

Add panel_verdict, panel_confidence, panel_rationale, panel_takes_json
columns to the signals table (additive, idempotent ALTER TABLE migration
for existing DBs). _report_row now reads the panel fields attach_panel
writes onto the SignalReport, so LLM panel verdicts stop evaporating on
process exit. Also documents the Oanda re-pin (round_trip_cost stays
$0.30 for cross-book comparability and the live TP gate; $0.65 is the
measured headline) and adds the feed-divergence / parity / shadow-scan
study tooling referenced by CLAUDE.md.

signal_log.py

@@ -60,20 +60,34 @@ CREATE TABLE IF NOT EXISTS signals (
     news_description TEXT,
     news_summary TEXT,
     events_json TEXT,
-    headlines_json TEXT
+    headlines_json TEXT,
+    panel_verdict TEXT,
+    panel_confidence REAL,
+    panel_rationale TEXT,
+    panel_takes_json TEXT
 );
 CREATE INDEX IF NOT EXISTS idx_signals_sym_tf_ts
     ON signals (symbol, timeframe, logged_at);
 """
 
+# Additive migration: older DBs created before the panel columns existed
+# get them added here. Idempotent — skips columns already present.
+_PANEL_COLS = (
+    ("panel_verdict", "TEXT"),
+    ("panel_confidence", "REAL"),
+    ("panel_rationale", "TEXT"),
+    ("panel_takes_json", "TEXT"),
+)
+
 _INSERT = """
 INSERT INTO signals (
     logged_at, source, symbol, timeframe, signal, score, confidence,
     quality, action, price, spread, market_regime, volatility_regime,
     mtf_json, setup_json, reasons_json, warnings_json,
     event_risk, event_description, news_sentiment, news_description,
-    news_summary, events_json, headlines_json
-) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+    news_summary, events_json, headlines_json,
+    panel_verdict, panel_confidence, panel_rationale, panel_takes_json
+) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
 """
 
 
@@ -207,6 +221,8 @@ def _report_row(
     events_json, headlines_json = _context_news_json(context)
 
     signal = getattr(report, "final_signal", None)
+    panel_takes = getattr(report, "panel_takes", None) or []
+    panel_takes_json = _dumps(panel_takes) if panel_takes else None
     return (
         datetime.now(timezone.utc).isoformat(),
         source,
@@ -232,6 +248,10 @@ def _report_row(
         getattr(report, "news_summary", "") or "",
         events_json,
         headlines_json,
+        getattr(report, "panel_verdict", None),
+        _finite(getattr(report, "panel_confidence", None)),
+        getattr(report, "panel_rationale", None),
+        panel_takes_json,
     )
 
 
@@ -251,11 +271,21 @@ class SignalLogger:
         self._lock = threading.Lock()
         with self._lock:
             self._conn.executescript(_SCHEMA)
+            self._migrate_panel_columns()
 
     @property
     def path(self) -> str:
         return self._path
 
+    def _migrate_panel_columns(self) -> None:
+        """Add panel_* columns to pre-existing tables (idempotent)."""
+        existing = {r[1] for r in self._conn.execute("PRAGMA table_info(signals)")}
+        for name, col_type in _PANEL_COLS:
+            if name not in existing:
+                self._conn.execute(
+                    f"ALTER TABLE signals ADD COLUMN {name} {col_type}")
+        self._conn.commit()
+
     def log(
         self,
         report: Any,