Add Railway deployment configuration

- Add Dockerfiles for backend (FastAPI) and frontend (nginx)
- Add railway.toml configs with health checks
- Add .dockerignore files for optimized builds
- Update config.py to auto-convert Railway DATABASE_URL format
- Add FRONTEND_URL env var for production CORS

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/Dockerfile

@@ -0,0 +1,22 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+# Install system dependencies
+RUN apt-get update && apt-get install -y \
+    gcc \
+    libpq-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Python dependencies
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application code
+COPY . .
+
+# Expose port (Railway uses PORT env variable)
+EXPOSE 8000
+
+# Run the application - use shell form to expand $PORT
+CMD uvicorn app.main:app --host 0.0.0.0 --port ${PORT:-8000}