Real-time collaboration — multiple observers per incident

[bgorzelic]

Description

On large incidents, multiple division supervisors and lookouts observe fire behavior simultaneously. Firevector should support real-time collaboration where multiple observers can contribute to an incident's observation set.

Proposed Architecture

Data Model Changes

• Add incidents table: { id, name, created_by, status, created_at }
• Add incident_members table: { incident_id, user_id, role } (roles: owner, observer, viewer)
• Observations get an optional incident_id FK — shared observations belong to an incident

Real-Time Updates

• Use Vercel's @vercel/postgres with LISTEN/NOTIFY or Supabase Realtime
• Alternative: Server-Sent Events (SSE) from Next.js API route
• Dashboard auto-updates when other observers add/edit observations

Invitation Flow

• Incident owner generates invite link or sends email invitation
• Invitee joins via link → added as observer
• Role-based permissions (owner can delete, observer can create/edit own, viewer read-only)

Acceptance Criteria

• Create incident and invite observers
• Multiple users can create observations under one incident
• Dashboard shows all incident observations (not just your own)
• Real-time updates when other observers add data
• Role-based access control (owner/observer/viewer)
• Incident-scoped map view with all observers' pins
• Works alongside individual (non-incident) observations

ADR Needed

This is a significant architectural change. Needs a design document covering:

• Data model changes and migration strategy
• Real-time technology selection
• Authorization model
• Impact on existing single-user features