agent_panel: persona/synthesizer advisory consensus module

ai-hedge-fund-style panel: 4 DeepSeek personas (macro, technical, risk,
contrarian) review a finished SignalReport concurrently on a
panel-private thread pool, then a synthesizer chair issues
AGREE/NEUTRAL/OPPOSE + confidence + rationale. Advisory/display-only by
construction: consumers attach post-hoc via attach_panel; the fields
live on SignalReport with empty defaults and analyze_from_dataframes
never touches them (backtest parity, locked by test).

Spend control on top of the shared 500/day client cap: max_panels_per_day
UTC budget (default 20), exact per-bar result cache, and a reuse TTL
keyed (symbol, tf, direction) so a persisting signal re-serves its
verdict across bars instead of burning 5 requests per bar. <2 valid
takes skips the synthesizer; any failure degrades to no panel.

Claude-Session: https://claude.ai/code/session_01SisdfkxnXNL9iZsXxN3T15

signal_aggregator.py

@@ -88,6 +88,15 @@ class SignalReport:
     news_description: str = ""
     news_summary: str = ""  # LLM market-context blurb (display-only)
 
+    # LLM agent-panel consensus (advisory/DISPLAY-ONLY). Populated
+    # post-hoc by consumers via agent_panel.attach_panel — NEVER inside
+    # analyze_from_dataframes (backtest parity) and never read by any
+    # gate or scoring path.
+    panel_verdict: str = ""        # "AGREE" / "NEUTRAL" / "OPPOSE" / ""
+    panel_confidence: float = 0.0
+    panel_rationale: str = ""
+    panel_takes: List[Dict] = field(default_factory=list)
+
     final_signal: SignalStrength = SignalStrength.NEUTRAL
     final_score: float = 0.0
     final_confidence: float = 0.0