Offline & Concurrency

import { Aside } from ‘@astrojs/starlight/components’;

Source: Master Spec v2.0, §15.

Exclusive editing

• Only one user/device may edit a particular Editable Version at a time. Others see that it is locked, with the editor’s name and useful device context. The lock is version-specific; other versions remain accessible.
• Admin may Force Unlock after confirmation; it records Admin, date, time.
• A disconnected former editor must never silently overwrite changes after another user receives the lock.

Local-first autosave

Autosave locally after meaningful changes: canvas create/move/edit/duplicate/delete, measurement changes, SOW configuration and price changes, proposal changes, layer/background presentation changes.

Sync automatically when internet returns. Status display: Saved Offline · Syncing · All Changes Synced · Sync Error. Sync Error retains local work, retries automatically, and offers Retry.

Offline capabilities

After map capture, the entire remaining workflow must work offline:

• Draw and edit canvas content; markup and layers.
• Edit SOW and specifications; apply cached Regular/Roofer prices.
• Edit prices and totals; create and edit proposals.
• Preview and generate Final Sketch JPG/PDF.
• Save versions locally for later sync.

Map search and initial satellite retrieval may require internet. Blank/Image/Camera estimates may start offline with cached catalog data.

Show the last price-list sync date/time while offline. Stale cached pricing never blocks work or export, and syncing new master prices later must not modify existing estimate snapshots.