| SQLite archive | Archive v2 schema, snapshot-level observation grouping, differential write path, v2 verification/delete bookkeeping, daily aggregate rebuilds, integrity report, v2 record reads, SQL diff/count/aggregate/provenance/consolidation-evidence APIs, large synthetic diff pagination coverage, formal timing/memory metrics, and XCTest coverage are in place; the legacy `archive_samples` mirror has been removed | Move Snapshots/Data Types from SwiftData previews to archive/cache DTOs |

 | Core Data cache | Initial programmatic Core Data model, full-cache rebuild service, read DTOs for observation/type/diff/health rows, and Dashboard archive-cache status wiring are in place | Move remaining export/report paths to cache DTOs and add targeted partial invalidation |

 | SwiftData cache | Exists; test builds now reset legacy prototype UI/archive/cache stores once for archive v2 so old SwiftData-only snapshots are not treated as backed-up observations. Metric timeout calibration, local device profile settings, operation logging, ContentView preview, Settings data maintenance, and legacy anomaly/count-drop review have moved outside SwiftData or been removed. Remaining SwiftData imports are inventoried in [`SwiftData-Retirement-Inventory.md`](SwiftData-Retirement-Inventory.md) | Treat as disposable prototype data; replace capture review actions and navigation handles before removing `ModelContainer` |

 | Diff/change explanation | SQL diff summaries, paged diff records, aggregate comparisons, and consolidation-evidence labels exist; legacy anomaly/count-drop review has been removed from active flows | Continue moving remaining SwiftData fallback detail paths to archive/cache DTOs |

 | Export | SQLite export preview, paged JSON writing, SHA256 manifest hashing, and `export_manifests` rows are in place for selected records and observation diffs | Fill remaining recovery-compatible envelope metadata, CSV export, relationship preservation, and reproducibility checks |

 | Legacy device support | Simplified detail UI mode is implemented for small/accessibility layouts and as a Settings toggle | Remove SwiftData dependency and validate lower deployment targets |

 - [ ] Replace direct SwiftData `@Query` dependencies for target screens.

 - [x] Dashboard status reads Core Data cached observation rows and cache health,

   with SwiftData retained only for capture/review actions.

 - [x] Observation detail uses cached summary/type rows plus SQLite diff summaries when archive observation ids exist.

 - [x] Data Types list rows prefer Core Data cached counts plus SQLite `diffSummary` when archive observation ids exist.

 - [x] Data type detail uses SQLite `diffSummary` when archive observation ids exist.

   `HealthProbe/Views/DataTypes/DataTypeTemporalDistributionView.swift` now read

   a `TemporalDistributionInput` DTO backed by `TypeCountDetailCache`; they no

   longer import SwiftData, query timeline snapshots, or require `ModelContext`.

 - `HealthProbe/Models/AnomalyRecord.swift`,

   `HealthProbe/Models/AnomalyType.swift`, and

   `HealthProbe/Services/AnomalyDetector.swift` were deleted. The app no longer

 struct SnapshotsView: View {

     @Environment(\.modelContext) private var modelContext

     @Query(sort: \HealthSnapshot.timestamp, order: .reverse) private var allSnapshots: [HealthSnapshot]

     @State private var viewModel = SnapshotsViewModel()

     @State private var profileMap: [String: LocalDeviceProfile] = [:]

     private var timelineReloadID: String {

         [

             String(allSnapshots.count),

         ].joined(separator: "|")

     }

     private var snapshotItems: [SnapshotListItem] {

         let baselines = viewModel.baselines(for: displayedSnapshots)

         if let archiveRows = viewModel.archiveRows {

             let snapshotsByObservationID = Dictionary(uniqueKeysWithValues: displayedSnapshots.compactMap { snapshot in

                     snapshot: snapshot,

                     baseline: snapshot.flatMap { baselines[$0.id] },

                     archiveRow: row,

                     showsDeltaSummary: viewModel.comparisonMode == .previous

                 )

             }

                 snapshot: snapshot,

                 baseline: baselines[snapshot.id] ?? nil,

                 archiveRow: nil,

                 showsDeltaSummary: viewModel.comparisonMode == .previous

             )

         }

             }

             .navigationTitle("Snapshots")

             .toolbar { toolbarContent }

             .task(id: timelineReloadID) {

                 loadDeviceProfiles()

                 await viewModel.loadArchiveRows()

                         snapshot: snapshot,

                         baseline: item.baseline,

                         archiveRow: item.archiveRow,

                         showsDeltaSummary: item.showsDeltaSummary,

                         isSelectedBaseline: viewModel.selectedBaseline?.id == snapshot.id,

                         profile: profileMap[snapshot.deviceID]

                     snapshot: nil,

                     baseline: item.baseline,

                     archiveRow: item.archiveRow,

                     showsDeltaSummary: item.showsDeltaSummary,

                     isSelectedBaseline: false,

                     profile: nil

         }

     }

     private func loadDeviceProfiles() {

         let profiles = LocalDeviceProfileStore.allProfiles()

         profileMap = Dictionary(uniqueKeysWithValues: profiles.compactMap {

     let snapshot: HealthSnapshot?

     let baseline: HealthSnapshot?

     let archiveRow: CachedArchiveObservationRow?

     let showsDeltaSummary: Bool

     var id: String {

     let snapshot: HealthSnapshot?

     let baseline: HealthSnapshot?

     let archiveRow: CachedArchiveObservationRow?

     let showsDeltaSummary: Bool

     let isSelectedBaseline: Bool

     let profile: LocalDeviceProfile?

             return parts.joined(separator: " • ")

         }

     }

     private var deltaSummaryColor: Color {

             return Color.healthyGreen

         }

     }

     private var deltaSummaryIconName: String {

             return hasChanges ? "arrow.triangle.2.circlepath" : "checkmark.circle"

         }

     }

     private var hasOSVersionChange: Bool {

 #Preview {

     SnapshotsView()

         .environment(AppSettings())

 }