feat: wizard config volume integration

- entrypoint.sh: wait for config file before starting uvicorn
- config.py: resolve DB URL from wizard config volume
- init_wizard.py: read config from file instead of HTTP
- Dockerfile: use entrypoint.sh

Dockerfile

@@ -15,9 +15,10 @@ RUN pip install --no-cache-dir -r requirements.txt
 
 # Copy application code
 COPY . .
+RUN chmod +x entrypoint.sh
 
 # Expose port
 EXPOSE 8000
 
-# Run the application
-CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]
+# Wait for wizard config, then start uvicorn
+ENTRYPOINT ["./entrypoint.sh"]