feat: add 5 dashboard features — dark mode, trade history, backtests, model insights, alerts

- Dark mode: class-based theme toggle with localStorage persistence and flash prevention
- Trade History (/trades): paginated table, stats cards, equity curve chart with DB API endpoints
- Backtest Viewer (/backtests): log parser for 35 backtest results, sidebar + detail + comparison tabs
- Model Insights: dashboard card + dialog showing feature importance, regime distribution, training history
- Alert/Signal Log (/alerts): signal stats, filterable table with execution tracking
- API: 8 new endpoints with psycopg2 DB connection pool
- Dark mode sweep across books page, about dialog, and all dashboard components
- Architecture docs rewritten with Mermaid diagrams (23 docs)
- README and FEATURES.md rewritten bilingual (Indonesian + English)
- main_live.py: write model_metrics.json on startup and retrain

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -10,8 +10,9 @@ WORKDIR /app
 COPY web-dashboard/api/requirements.txt requirements.txt
 RUN pip install --no-cache-dir -r requirements.txt
 
-# Copy only the API code
+# Copy the API code
 COPY web-dashboard/api/main.py main.py
+COPY web-dashboard/api/db.py db.py
 
 # Create data directory (will be overridden by volume mount)
 RUN mkdir -p data