agent_panel: alerts use the macro persona's verdict; all 4 takes still logged

agent_panel.verdict_source defaults to "macro": the macro take's stance is the
verdict, the synthesizer call is skipped (4 LLM calls per panel instead of 5);
"chair" restores the four-voice consensus + OPPOSE guard. Verdict source is
cached per mode and logged (panel_verdict_source). 406 tests.

Claude-Session: https://claude.ai/code/session_01FC4s6VCURFte4dub4xKxYL

signal_log.py

@@ -169,6 +169,7 @@ _ADDITIVE_SIGNAL_COLS = (
     ("bar_range_median", "REAL"),
     ("scan_kind", "TEXT"),
     ("config_fingerprint", "TEXT"),
+    ("panel_verdict_source", "TEXT"),
 )
 
 # Read-side compatibility view `signals_with_news`: legacy rows keep
@@ -779,6 +780,7 @@ class SignalLogger:
         created_at: Optional[str] = None,
         cache_status: Optional[str] = None,
         payload_hash: Optional[str] = None,
+        verdict_source: Optional[str] = None,
     ) -> None:
         """Fill panel provenance; seeds an outcome only for rows that
         log() did not already seed (rows written by an older process)."""
@@ -804,11 +806,12 @@ class SignalLogger:
                 " panel_created_at=COALESCE(?, panel_created_at),"
                 " panel_cache_status=COALESCE(?, panel_cache_status),"
                 " panel_payload_hash=COALESCE(?, panel_payload_hash),"
+                " panel_verdict_source=COALESCE(?, panel_verdict_source),"
                 " advisory_outcome_status=COALESCE(advisory_outcome_status, ?),"
                 " advisory_outcome_json=COALESCE(advisory_outcome_json, ?)"
                 " WHERE id=?",
                 (verdict, confidence, rationale, takes_json,
-                 created_at, cache_status, payload_hash,
+                 created_at, cache_status, payload_hash, verdict_source,
                  advisory_status, advisory_json, rowid))
             self._conn.commit()
 
@@ -1205,7 +1208,8 @@ def log_panel_update(report: Any) -> None:
             _dumps(getattr(report, "panel_takes", None) or []),
             created_at=getattr(report, "panel_created_at", "") or None,
             cache_status=getattr(report, "panel_cache_status", "") or None,
-            payload_hash=getattr(report, "panel_payload_hash", "") or None)
+            payload_hash=getattr(report, "panel_payload_hash", "") or None,
+            verdict_source=getattr(report, "panel_verdict_source", "") or None)
     except Exception:
         logger.warning("signal_log: failed to persist panel verdict",
                        exc_info=True)