feat: add strategy variant lab and signal context snapshots

Backtest report now includes research-only hold-to-horizon portfolio variants comparing raw vs residual 12-1 momentum, cutoff 80 vs 90, max 10 vs 15 positions, and SPY-200 risk scaling. A dynamic research recommendation panel flags residual momentum, cutoff 90, or regime scaling only when transparent promotion rules pass.

Adds signal_context_snapshots with migration 016 and captures one point-in-time context row per newly generated TradeSetup: setup fields, composite/dimensions, latest sentiment, latest fundamentals, and strategy_version=momentum_12_1_rr_time_v1. This is forward-only; no historical sentiment/fundamental backfill is attempted.

No live gate, paper-trade exit, or production ranking behavior changes.

Verification: 458 backend tests pass, ruff check app/ clean, frontend npm run build clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/components/signals/BacktestPanel.tsx

@@ -6,7 +6,7 @@ import { Callout } from '../ui/Callout';
 import { Disclosure } from '../ui/Disclosure';
 import { Section } from '../ui/Section';
 import { useToast } from '../ui/Toast';
-import type { BacktestBucket, BacktestPortfolioPolicy } from '../../lib/types';
+import type { BacktestBucket, BacktestPortfolioPolicy, BacktestStrategyVariant } from '../../lib/types';
 
 function fmtR(v: number | null | undefined): string {
   if (v === null || v === undefined) return '—';
@@ -206,6 +206,25 @@ export function BacktestPanel() {
               </div>
             )}
 
+            {report.research_recommendation && report.research_recommendation.items.length > 0 && (
+              <div className="glass border border-emerald-400/15 p-4">
+                <p className="section-index">Research candidates</p>
+                <ul className="mt-2 space-y-1">
+                  {report.research_recommendation.items.map((item) => (
+                    <li
+                      key={item.topic + item.text}
+                      className={`text-xs ${item.candidate ? 'text-emerald-400' : 'text-gray-400'}`}
+                    >
+                      {item.text}
+                    </li>
+                  ))}
+                </ul>
+                {report.research_recommendation.note && (
+                  <p className="mt-2 text-[11px] text-gray-600">{report.research_recommendation.note}</p>
+                )}
+              </div>
+            )}
+
             <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-4">
               <Stat
                 label="Qualified Hit Rate"
@@ -516,6 +535,60 @@ export function BacktestPanel() {
               </div>
             )}
 
+            {report.strategy_variants && report.strategy_variants.variants.length > 0 && (
+              <div>
+                <p className="mb-2 text-xs font-medium uppercase tracking-widest text-gray-500">
+                  Strategy variants
+                </p>
+                <p className="mb-2 text-[11px] text-gray-500">
+                  {report.strategy_variants.note ?? 'Research-only portfolio variants.'}{' '}
+                  <span className="text-gray-300">
+                    Residual momentum stays research-only until a variant beats production under the promotion rules.
+                  </span>
+                </p>
+                <div className="glass overflow-x-auto">
+                  <table className="w-full text-sm">
+                    <thead>
+                      <tr className="border-b border-white/[0.06] text-left text-xs uppercase tracking-wider text-gray-500">
+                        <th className="px-4 py-2.5">Variant</th>
+                        <th className="px-4 py-2.5 text-right">Rank</th>
+                        <th className="px-4 py-2.5 text-right">Cutoff</th>
+                        <th className="px-4 py-2.5 text-right">Max Pos</th>
+                        <th className="px-4 py-2.5 text-right">Risk</th>
+                        <th className="px-4 py-2.5 text-right">CAGR</th>
+                        <th className="px-4 py-2.5 text-right">Max DD</th>
+                        <th className="px-4 py-2.5 text-right">Sharpe</th>
+                        <th className="px-4 py-2.5 text-right">Total Ret</th>
+                        <th className="px-4 py-2.5 text-right">Trades</th>
+                        <th className="px-4 py-2.5 text-right">Skipped</th>
+                      </tr>
+                    </thead>
+                    <tbody>
+                      {report.strategy_variants.variants.map((row: BacktestStrategyVariant) => (
+                        <tr key={row.variant} className="border-b border-white/[0.04]">
+                          <td className="px-4 py-2.5 font-medium text-gray-200">{row.label}</td>
+                          <td className="num px-4 py-2.5 text-right text-gray-300">{row.ranking}</td>
+                          <td className="num px-4 py-2.5 text-right text-gray-300">{row.cutoff.toFixed(0)}</td>
+                          <td className="num px-4 py-2.5 text-right text-gray-300">{row.max_positions}</td>
+                          <td className="num px-4 py-2.5 text-right text-gray-300">
+                            {row.risk_scale === 'spy_200' ? '0.5-1.0%' : `${row.risk_per_trade_pct.toFixed(1)}%`}
+                          </td>
+                          <td className={`num px-4 py-2.5 text-right ${rColor(row.cagr_pct)}`}>{fmtSignedPct(row.cagr_pct)}</td>
+                          <td className="num px-4 py-2.5 text-right text-amber-400">−{row.max_drawdown_pct.toFixed(1)}%</td>
+                          <td className="num px-4 py-2.5 text-right text-gray-200">
+                            {row.sharpe === null ? '—' : row.sharpe.toFixed(2)}
+                          </td>
+                          <td className={`num px-4 py-2.5 text-right ${rColor(row.total_return_pct)}`}>{fmtSignedPct(row.total_return_pct)}</td>
+                          <td className="num px-4 py-2.5 text-right text-gray-300">{row.trades}</td>
+                          <td className="num px-4 py-2.5 text-right text-gray-500">{row.skipped_book_full}</td>
+                        </tr>
+                      ))}
+                    </tbody>
+                  </table>
+                </div>
+              </div>
+            )}
+
             {report.signal_eval && report.signal_eval.length > 0 && (
               <div>
                 <p className="mb-2 text-xs font-medium uppercase tracking-widest text-gray-500">

frontend/src/lib/types.ts

@@ -294,6 +294,11 @@ export interface BacktestRecommendation {
   note?: string;
 }
 
+export interface BacktestResearchRecommendation {
+  items: { topic: string; text: string; candidate?: boolean }[];
+  note?: string;
+}
+
 export interface BacktestPortfolioSim {
   params: {
     starting_capital: number;
@@ -307,6 +312,21 @@ export interface BacktestPortfolioSim {
   note?: string;
 }
 
+export interface BacktestStrategyVariant extends BacktestPortfolioPolicy {
+  variant: string;
+  label: string;
+  ranking: 'raw' | 'residual' | string;
+  cutoff: number;
+  max_positions: number;
+  risk_per_trade_pct: number;
+  risk_scale: string | null;
+}
+
+export interface BacktestStrategyVariants {
+  variants: BacktestStrategyVariant[];
+  note?: string;
+}
+
 export interface BacktestGateAblationRow extends BacktestBucket {
   variant: string;
   // The same variant graded under the hold-to-horizon time exit.
@@ -347,7 +367,9 @@ export interface BacktestReport {
   gate_ablation_note?: string;
   time_exit_sweep?: BacktestTimeExitRow[];
   portfolio_sim?: BacktestPortfolioSim;
+  strategy_variants?: BacktestStrategyVariants;
   recommendation?: BacktestRecommendation;
+  research_recommendation?: BacktestResearchRecommendation;
   signal_eval?: BacktestSignalEvalRow[];
   signal_eval_note?: string;
   note: string;