[Issue]: Write local sync setup guide

[dawidurbanski]

[Issue]: Write Local Sync Setup Guide

Parent Epic: #57 - UDL as Production Data Layer
Phase: 6 - Documentation
Estimated Time: 0.5 day

Summary

Write documentation explaining how developers can configure their local UDL instance to sync with a remote UDL server via WebSocket and the sync API.

Context from Epic

The epic describes the local sync setup:

remote: {
  url: 'https://udl.example.com/graphql',  // Remote UDL URL
  websockets: true,                         // Enable WebSocket sync
}

Developers need a guide to connect their local dev environment to a production UDL instance for real-time updates.

Technical Specification

Documentation Content

Local Sync Setup Guide:

1. Introduction

   • Why sync local with remote
   • Architecture: local UDL ↔ remote UDL

2. Configuration

   // udl.config.ts
   export const config = defineConfig({
     port: 4000,
     plugins: [...],
     remote: {
       url: 'https://udl.example.com/graphql',
       websockets: true,
     },
   });

3. How Sync Works

   • Initial sync on startup (via /_sync endpoint)
   • Real-time updates via WebSocket
   • Handling disconnections and reconnection

4. WebSocket Events

   • node:created, node:updated, node:deleted
   • Subscribing to specific node types

5. Troubleshooting

   • Connection issues
   • Sync lag
   • Debugging tips

Files to Create

• docs/content/4.deployment/7.local-sync.md

Implementation Tasks

• Write introduction explaining local/remote sync
• Document configuration options
• Explain sync flow (initial + WebSocket)
• Document WebSocket protocol
• Add troubleshooting section

Acceptance Criteria

• Guide explains local-to-remote sync setup
• Configuration examples are clear
• WebSocket events are documented
• Troubleshooting covers common issues

Dependencies

• Blocked by: [Issue]: Add sync query API for partial updates #65 (sync API), [Issue]: Implement WebSocket server for real-time sync #66 (WebSocket server)
• Blocks: None
• Related: [Epic]: UDL as Production Data Layer #57 (parent epic)

Definition of Done

• Documentation complete and reviewed
• Examples tested
• PR reviewed and merged