fix: only count matured setups in the live track record

The outcome stats were dominated by quick stop-outs: near stops resolve as losses
within days while far targets take weeks, so a young sample (mostly pending,
0 expired) skewed sharply negative (e.g. 13.8% hit / -0.46R vs the backtest's
35.8% / +0.18R) — a maturation artifact, not a real result.

get_performance_stats now counts only setups whose full ~30-day window has
elapsed (_MATURITY_DAYS), so winners had as long as losers (unbiased, and
comparable to the backtest). A new `maturing` count reports the younger setups
held back. The Track Record UI relabels "Evaluated" -> "Matured", shows the
maturing count, and explains the window in the empty state + methodology note.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/components/signals/TrackRecordPanel.tsx

@@ -171,7 +171,10 @@ export function TrackRecordPanel() {
             neither level hit within 30 trading days <span className="text-gray-300">expire</span> at
             0R. Avg R is the expectancy per trade: wins earn their R:R ratio, losses cost −1R — a
             positive value means the signals have been profitable on a risk-adjusted basis. The
-            evaluator runs nightly after OHLCV collection.
+            evaluator runs nightly after OHLCV collection. Only setups whose full 30-day window has
+            elapsed are counted — younger ones show as <span className="text-gray-300">maturing</span>,
+            since near stops resolve in days while far targets need time, so early numbers would skew
+            negative.
           </p>
         </Disclosure>
         <div className="flex shrink-0 items-center gap-2">
@@ -198,10 +201,12 @@ export function TrackRecordPanel() {
 
       {data && data.overall.total === 0 && (
         <Callout variant="empty">
-          {qualifiedOnly
-            ? 'No evaluated setups meet the activation thresholds yet. Untick "Qualified signals only" to see all evaluated setups, or wait for more outcomes.'
-            : 'No evaluated setups yet. Outcomes appear once setups are old enough for their stop or target to be hit — the evaluator runs nightly, or click Evaluate Now.'}
-          {data.pending > 0 && ` ${data.pending} setup${data.pending === 1 ? '' : 's'} pending evaluation.`}
+          {data.maturing > 0
+            ? `No setups have completed their ~30-day evaluation window yet — ${data.maturing} still maturing. ` +
+              'Stats appear once a setup’s full window has elapsed; counting them earlier would skew toward quick stop-outs.'
+            : qualifiedOnly
+              ? 'No matured setups meet the activation thresholds yet. Untick "Qualified signals only" to see all, or wait for more outcomes.'
+              : 'No matured setups yet. Outcomes appear once setups complete their evaluation window — the evaluator runs nightly, or click Evaluate Now.'}
         </Callout>
       )}
 
@@ -226,9 +231,9 @@ export function TrackRecordPanel() {
               sub="cumulative risk-adjusted result"
             />
             <StatCard
-              label="Evaluated"
+              label="Matured"
               value={String(data.overall.total)}
-              sub={`${data.pending} pending · ${data.overall.expired} expired`}
+              sub={`${data.maturing} maturing · ${data.overall.expired} expired`}
             />
           </div>
 

frontend/src/lib/types.ts

@@ -153,6 +153,7 @@ export interface OutcomeBucketStats {
 export interface PerformanceStats {
   overall: OutcomeBucketStats;
   pending: number;
+  maturing: number;
   by_direction: Record<string, OutcomeBucketStats>;
   by_action: Record<string, OutcomeBucketStats>;
   by_confidence: Record<string, OutcomeBucketStats>;