Add official Polymarket API support, one-click setup, and redesigned README

- Add TRADE_API_MODE setting to switch between official (public, no auth) and internal API
- Implement _fetch_trades_official() using Polymarket data-api /trades endpoint
- Default to official API so users can run without private API access
- Add interactive setup.sh that guides users through API key configuration
- Add Makefile with common commands (setup, run, dashboard, etc.)
- Add Dockerfile and .dockerignore for container deployment
- Redesign README with badges, feature tables, mermaid diagram, architecture
- Clean up .env.example with organized sections and signup links
- Update pyproject.toml dependencies to match requirements.txt

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,17 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+# Install dependencies first (cached layer)
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application code
+COPY src/ src/
+COPY pyproject.toml .
+
+# Create data directories
+RUN mkdir -p data reports daily_briefings
+
+# Default command
+CMD ["python", "-m", "src.main", "run"]