feat(platform): summarize missing vehicle sources

vehicle-data-platform/apps/api/internal/platform/handler_test.go

@@ -185,6 +185,9 @@ func TestHandlerVehicleCoverageSummary(t *testing.T) {
 	if body.Data.OnlineVehicles != 1 || body.Data.UnboundVehicles != 0 {
 		t.Fatalf("coverage summary should expose filtered online and binding totals, got %+v", body.Data)
 	}
+	if len(body.Data.MissingSources) == 0 {
+		t.Fatalf("coverage summary should expose missing source counts, got %+v", body.Data)
+	}
 }
 
 func TestSplitCSVEmptyReturnsEmptySlice(t *testing.T) {

vehicle-data-platform/apps/api/internal/platform/mock_store.go

@@ -168,6 +168,15 @@ func (m *MockStore) VehicleCoverageSummary(ctx context.Context, query url.Values
 			summary.UnboundVehicles++
 		}
 	}
+	for _, protocol := range canonicalVehicleProtocols {
+		missing := 0
+		for _, row := range coverage.Items {
+			if !containsString(row.Protocols, protocol) {
+				missing++
+			}
+		}
+		summary.MissingSources = append(summary.MissingSources, MissingSourceStat{Protocol: protocol, Count: missing})
+	}
 	return summary, nil
 }
 

vehicle-data-platform/apps/api/internal/platform/model.go

@@ -65,12 +65,13 @@ type VehicleCoverageRow struct {
 }
 
 type VehicleCoverageSummary struct {
-	TotalVehicles        int `json:"totalVehicles"`
-	OnlineVehicles       int `json:"onlineVehicles"`
-	SingleSourceVehicles int `json:"singleSourceVehicles"`
-	MultiSourceVehicles  int `json:"multiSourceVehicles"`
-	NoDataVehicles       int `json:"noDataVehicles"`
-	UnboundVehicles      int `json:"unboundVehicles"`
+	TotalVehicles        int                 `json:"totalVehicles"`
+	OnlineVehicles       int                 `json:"onlineVehicles"`
+	SingleSourceVehicles int                 `json:"singleSourceVehicles"`
+	MultiSourceVehicles  int                 `json:"multiSourceVehicles"`
+	NoDataVehicles       int                 `json:"noDataVehicles"`
+	UnboundVehicles      int                 `json:"unboundVehicles"`
+	MissingSources       []MissingSourceStat `json:"missingSources"`
 }
 
 type VehicleIdentityResolution struct {

vehicle-data-platform/apps/api/internal/platform/production_store.go

@@ -297,9 +297,30 @@ func (s *ProductionStore) VehicleCoverageSummary(ctx context.Context, query url.
 	); err != nil {
 		return VehicleCoverageSummary{}, err
 	}
+	missingSources, err := s.coverageMissingSourceStats(ctx, query)
+	if err != nil {
+		return VehicleCoverageSummary{}, err
+	}
+	summary.MissingSources = missingSources
 	return summary, nil
 }
 
+func (s *ProductionStore) coverageMissingSourceStats(ctx context.Context, query url.Values) ([]MissingSourceStat, error) {
+	out := make([]MissingSourceStat, 0, len(canonicalVehicleProtocols))
+	for _, protocol := range canonicalVehicleProtocols {
+		next := copyValues(query)
+		next.Set("missingProtocol", protocol)
+		next.Set("limit", "1")
+		next.Set("offset", "0")
+		page, err := s.VehicleCoverage(ctx, next)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, MissingSourceStat{Protocol: protocol, Count: page.Total})
+	}
+	return out, nil
+}
+
 func (s *ProductionStore) VehicleRealtime(ctx context.Context, query url.Values) (Page[VehicleRealtimeRow], error) {
 	built := buildVehicleRealtimeSQL(query)
 	total := 0