feat: add Signal Timeline chart to Signal Confluence panel

- New ConfluenceChart component renders daily price as area chart
- Overlays colored dot markers at each signal fire date (green=bull,
  red=bear, amber=exit)
- Detects entry zones (2+ bull signals within 5 days) and exit zones
  (2+ bear/exit signals) and shades them on the chart
- Custom tooltip shows price + which signals fired on hover
- Fetches candles and signal history in parallel on mount
- Placed between Slot Evidence and Reliability Scorecard sections

app/src/components/ConfluencePanel.tsx

@@ -4,6 +4,7 @@ import { api } from '@/lib/trpc';
 import { useActiveSymbol } from '@/stores/active-symbol-store';
 import { CollapsibleSection } from '@/components/CollapsibleSection';
 import { SymbolAutocomplete } from '@/components/SymbolAutocomplete';
+import { ConfluenceChart } from '@/components/ConfluenceChart';
 
 // ---------------------------------------------------------------------------
 // Types (subset of server types for display)
@@ -210,6 +211,13 @@ export function ConfluencePanel() {
         </CollapsibleSection>
       )}
 
+      {/* Signal Timeline chart */}
+      {symbol && (
+        <CollapsibleSection title="Signal Timeline" defaultOpen>
+          <ConfluenceChart symbol={symbol} />
+        </CollapsibleSection>
+      )}
+
       {/* Scorecard */}
       {scorecard && scorecard.slots.length > 0 && (
         <CollapsibleSection title="Reliability Scorecard">