Add configurable minimum quality score setting

- Added minQualityScore to TradingConfig (default: 60)
- Updated settings UI with slider control (0-100, step 5)
- Updated check-risk endpoint to use config value
- Made scoreSignalQuality function accept minScore parameter
- Updated API to read/write MIN_QUALITY_SCORE env variable
- Allows users to adjust quality threshold from settings page

app/settings/page.tsx

@@ -26,6 +26,7 @@ interface TradingSettings {
   MAX_DAILY_DRAWDOWN: number
   MAX_TRADES_PER_HOUR: number
   MIN_TIME_BETWEEN_TRADES: number
+  MIN_QUALITY_SCORE: number
   SLIPPAGE_TOLERANCE: number
   DRY_RUN: boolean
 }
@@ -393,6 +394,15 @@ export default function SettingsPage() {
               step={1}
               description="Minimum wait time between trades to prevent overtrading."
             />
+            <Setting
+              label="Min Quality Score (0-100)"
+              value={settings.MIN_QUALITY_SCORE}
+              onChange={(v) => updateSetting('MIN_QUALITY_SCORE', v)}
+              min={0}
+              max={100}
+              step={5}
+              description="Minimum signal quality score required to accept a trade. Signals below this score will be blocked."
+            />
           </Section>
 
           {/* Execution */}