Field Sync Tier 2: Manual Network Push to Central Instance

[spydmobile]

Parent Issue

Sub-issue of #137 (Field Sync — Export/Import Between Nomad Instances)

Depends on Tier 1 (Manual Export/Import via ZIP) being complete.

Summary

Network-based manual sync — user clicks "Sync to Central" and the field instance pushes models to the central instance's import endpoint over HTTP.

Scope

• Central instance URL configurable in settings (.env or settings UI)
• "Sync to Central" button in dashboard
• POSTs the export bundle to the central instance's POST /api/v1/import endpoint
• Per-model sync status indicator: synced / pending / error
• Sync log showing what was pushed and when
• Auth: field instance authenticates to central (token or shared key)

Not In Scope

• Auto-detection of central instance availability
• Background polling
• Auto-push on reconnect