feat: validate transport incident requires truck_id

Add 'transport' to INCIDENT_TYPES; add truck_id field to IncidentInput;
reject transport submissions missing truck_id.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CPf5Rc8QPx6V8KLEEgfKEQ

lib/incidents/validate.ts

@@ -1,4 +1,4 @@
-export const INCIDENT_TYPES = ['injury', 'near_miss', 'hazard', 'asset_damage', 'environmental', 'security', 'fire'] as const
+export const INCIDENT_TYPES = ['injury', 'near_miss', 'hazard', 'asset_damage', 'environmental', 'security', 'fire', 'transport'] as const
 export const MEDICAL_STATUSES = ['none', 'first_aid', 'medical_treatment', 'lti'] as const
 
 export type IncidentType = typeof INCIDENT_TYPES[number]
@@ -12,6 +12,7 @@ export interface IncidentInput {
   medical_status?: MedicalStatus
   asset_involved: boolean
   type_details?: Record<string, unknown>
+  truck_id?: string | null
 }
 
 // Whitelisted type-specific intake fields per incident type (PRD §3).
@@ -76,6 +77,8 @@ export function validateIncidentInput(input: IncidentInput): { ok: boolean; erro
   if (!INCIDENT_TYPES.includes(input.incident_type)) errors.push('incident_type is invalid')
   if (input.injury_involved && !input.medical_status) errors.push('medical_status is required when injury is involved')
   if (input.medical_status && !MEDICAL_STATUSES.includes(input.medical_status)) errors.push('medical_status is invalid')
+  if (input.incident_type === 'transport' && !input.truck_id?.trim())
+    errors.push('truck_id is required for transport incidents')
 
   return { ok: errors.length === 0, errors }
 }