fix: Add adaptive leverage env vars to docker-compose.yml

Added 4 adaptive leverage environment variables to docker-compose.yml
so they are properly passed to the container:

- USE_ADAPTIVE_LEVERAGE (default: true)
- HIGH_QUALITY_LEVERAGE (default: 5)
- LOW_QUALITY_LEVERAGE (default: 1)
- QUALITY_LEVERAGE_THRESHOLD (default: 95)

Without these in the environment section, the container couldn't
access them via process.env, causing the settings API to return null.

Now the settings UI can properly load and save adaptive leverage
configuration via the web interface.

docker-compose.yml

@@ -45,6 +45,12 @@ services:
       MIN_SIGNAL_QUALITY_SCORE_LONG: ${MIN_SIGNAL_QUALITY_SCORE_LONG:-90}
       MIN_SIGNAL_QUALITY_SCORE_SHORT: ${MIN_SIGNAL_QUALITY_SCORE_SHORT:-95}
       
+      # Adaptive Leverage (Dec 1, 2025 - quality-based position sizing)
+      USE_ADAPTIVE_LEVERAGE: ${USE_ADAPTIVE_LEVERAGE:-true}
+      HIGH_QUALITY_LEVERAGE: ${HIGH_QUALITY_LEVERAGE:-5}
+      LOW_QUALITY_LEVERAGE: ${LOW_QUALITY_LEVERAGE:-1}
+      QUALITY_LEVERAGE_THRESHOLD: ${QUALITY_LEVERAGE_THRESHOLD:-95}
+      
       # Database (if using PostgreSQL)
       DATABASE_URL: ${DATABASE_URL:-postgresql://postgres:postgres@postgres:5432/trading_bot_v4}