A visit is #1042, not 4cc216ca-dad3-4958-bb96-5f5a82022cf8

Every other thing in this product a person refers to already had a
readable reference: a shop is chennai, a camera cam1, a customer V-42, a
person their email. An audit of every list response found exactly one
gap, and it was the row people look at most - the arrivals feed showed a
visit as 36 hex characters.

012 argued no route takes a visit id so none was needed. That is true of
routing and false of everything else: it is what the feed shows, what a
support conversation quotes, and what somebody reading an API response
judges the product by.

Migration 014 mirrors the visitor scheme exactly - per client, so it
discloses no platform-wide volume, and beside the uuid rather than
instead of it. A stored counter is affordable on the busiest table
because visits from one tenant are already serialised by the consumer's
SetOrderMatters(true), so it adds no contention that was not already
there. A derived reference was the alternative and does not work:
several people through one door share occurred_at to the microsecond,
which is the collision 004 exists to handle.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KGcjxF1cNLcuwc3DAPcnfj

server/internal/store/api_arrivals.go

@@ -12,7 +12,7 @@ import (
 // mean the first poll of a feed and every poll after it returned different
 // shapes, which is the kind of bug that only shows up under load.
 const arrivalColumns = `
-	vi.id::text, vi.seq, vi.occurred_at, vi.site_id::text, si.name, si.slug, vi.camera_id,
+	vi.id::text, vi.seq, COALESCE(vi.number, 0), vi.occurred_at, vi.site_id::text, si.name, si.slug, vi.camera_id,
 	vi.is_new_visitor, vi.similarity, vi.quality, vi.attributes, vi.image_key,
 	COALESCE(vi.visitor_id::text, ''),
 	COALESCE(vs.number, 0),
@@ -112,13 +112,14 @@ func (s *Store) Arrivals(ctx context.Context, q api.ArrivalQuery) ([]api.Arrival
 		var at time.Time
 		var sim, qual *float64
 		var imageKey string
-		var number int64
-		if err := rows.Scan(&a.VisitID, &a.Seq, &at, &a.SiteID, &a.Site, &a.SiteSlug, &a.CameraID,
+		var number, visitNumber int64
+		if err := rows.Scan(&a.VisitID, &a.Seq, &visitNumber, &at, &a.SiteID, &a.Site, &a.SiteSlug, &a.CameraID,
 			&a.IsNew, &sim, &qual, &a.Attributes, &imageKey,
 			&a.VisitorID, &number, &a.Label, &a.Name); err != nil {
 			return nil, err
 		}
 		a.VisitorRef = api.VisitorRef(number)
+		a.VisitRef = api.VisitRef(visitNumber)
 		a.OccurredAt = at.UTC().Format(time.RFC3339Nano)
 		if sim != nil {
 			a.Similarity = *sim