feat: Migrate data storage to PostgreSQL with schema setup, initialization script, and update documentation

Dockerfile

@@ -28,9 +28,6 @@ RUN bun install --frozen-lockfile --production
 COPY --from=base /app/dist ./dist
 COPY --from=base /app/src ./src
 
-# Create data directory for persistent storage
-RUN mkdir -p /app/data
-
 # Expose port (if needed for health checks)
 EXPOSE 3000