Migrate the sync file layer onto the IndieSync package

Replaces the app-local copies of the extracted storage core with the
IndieSync 0.1.0 package (pinned from the new tag): ICloudFileManager ->
DocumentFileStore + TombstoneStore, ICloudFileMonitor ->
MetadataObserver (batched events with the content-date churn gate),
and the shared ULID / DocumentCoder / Tombstone / VersionedDocument
pieces. SyncEngine stays app-specific and is rewired onto the package
types; documents rename currentSchema -> currentSchemaVersion to adopt
the package protocol. ULID.make() remains as a shim minting the string
form the app keys on.

Behavior-preserving: identical JSON bytes (same coder config), same
stub wire format (kind encodes as the same strings), same soft-delete
ordering, same 30-day prune. WorkoutDocument keeps its local-calendar
month bucketing rather than adopting TimeBucketedLayout's UTC paths --
changing derivation would strand existing files. The watch target
links the package too (ULID + DocumentCoder via Shared); iOS, watchOS,
and widget targets all build.

CLAUDE.md

@@ -24,20 +24,19 @@ A workout tracking app for iPhone and Apple Watch, built with Swift 6 and SwiftU
 ### Persistence & Sync (iCloud Drive documents)
 - **Source of truth**: JSON documents in the iCloud Drive container `iCloud.dev.rzen.indie.Workouts`. One file per aggregate: `Splits/<ULID>.json` and `Workouts/YYYY/MM/<ULID>.json` (month-bucketed; ULIDs sort chronologically).
 - **SwiftData cache**: `WorkoutsModelContainer` (`Shared/Persistence/`) builds a local SwiftData store as a *rebuildable read-through cache*, created with `cloudKitDatabase: .none`. It is wiped on a schema-version bump or an iCloud account change. Views read it via `@Query`.
-- **One-way data flow (iPhone)**: view → `SyncEngine.save(...)` writes a file → `ICloudFileMonitor` (an `NSMetadataQuery`) emits a delta → `CacheMapper` upserts SwiftData → `@Query` views refresh. The phone is the **sole writer** of iCloud Drive.
+- **One-way data flow (iPhone)**: view → `SyncEngine.save(...)` writes a file → `MetadataObserver` (an `NSMetadataQuery`) emits a delta batch → `CacheMapper` upserts SwiftData → `@Query` views refresh. The phone is the **sole writer** of iCloud Drive.
-- **Key types** (under `Workouts/Sync/`):
+- **Key types**:
-  - `SyncEngine` (`@Observable @MainActor`) — orchestrator. `connect()` resolves the ubiquity container and reconciles; `save`/`delete` write files; `handle(event:)` applies observer deltas; `ingestFromWatch(_:)` writes + upserts the cache directly. Exposes `iCloudStatus` and an `onCacheChanged` callback.
+  - `SyncEngine` (`@Observable @MainActor`, in `Workouts/Sync/`) — the app-specific orchestrator. `connect()` resolves the ubiquity container and reconciles; `save`/`delete` write files; `handle(_:)` applies observer delta batches; `ingestFromWatch(_:)` writes + upserts the cache directly. Exposes `iCloudStatus` and an `onCacheChanged` callback.
-  - `ICloudFileManager` (`actor`) — all `NSFileCoordinator` file I/O, off the main thread.
+  - The file-side core comes from the **IndieSync** SPM package (`https://git.rzen.dev/rzen/indie-sync.git`): `DocumentFileStore` (actor — all `NSFileCoordinator` I/O, conflict resolution, eviction-safe reads, placeholder-aware enumeration), `TombstoneStore` (soft-delete stubs, resurrection veto, grace-period pruning), `MetadataObserver` (`@MainActor` — wraps the `NSMetadataQuery`, emitting added/modified/removed batches as an `AsyncStream`), plus `ULID`, `DocumentCoder`, `SyncError`, and the `VersionedDocument` protocol. See the `icloud-sync-engine` skill for the architecture invariants.
-  - `ICloudFileMonitor` (`@MainActor`) — wraps the `NSMetadataQuery`, emitting added/modified/removed deltas as an `AsyncStream`.
 - **Soft deletes**: a delete writes a `Tombstone` to `Stubs/<id>.json` then removes the live file (so offline devices still learn of the delete); stubs are pruned after a 30-day grace period.
 - **iCloud is required**: `RootGateView` (`Workouts/Views/`) gates the app on `SyncEngine.iCloudStatus` — there is no local-only mode.
 
 ### Data Layer (three shapes + a stateless mapper)
 All in `Shared/Model/`:
-- **Codable documents** (`Documents.swift`) — the on-disk / wire format: `SplitDocument` (embeds `[ExerciseDocument]`) and `WorkoutDocument` (embeds `[WorkoutLogDocument]`), plus `Tombstone`, a `VersionedDocument` schema gate (quarantines files from newer app versions), and a shared `DocumentCoder`.
+- **Codable documents** (`Documents.swift`) — the on-disk / wire format: `SplitDocument` (embeds `[ExerciseDocument]`) and `WorkoutDocument` (embeds `[WorkoutLogDocument]`), conforming to IndieSync's `VersionedDocument` schema gate (quarantines files from newer app versions). `Tombstone` and `DocumentCoder` come from IndieSync. `WorkoutDocument.relativePath` keeps the app's own local-calendar month bucketing (predates IndieSync's UTC `TimeBucketedLayout`; changing it would strand existing files).
 - **SwiftData `@Model` cache entities** (`Entities.swift`) — `Split`, `Exercise`, `Workout`, `WorkoutLog`; each keyed by a stable `id: String` ULID (`@Attribute(.unique)`), with cascade relationships and a `jsonRelativePath` back to its file.
 - **Stateless mappers** (`Mappers.swift`) — `init(from: entity)` for cache → document; `CacheMapper.upsert…` for document → cache (used *only* by the observer, reconcile, and the watch bridge).
-- **Identifiers** (`ULID.swift`) — 26-char Crockford base32, chronologically sortable.
+- **Identifiers** (`ULID.swift`) — a thin shim over IndieSync's `ULID`: `ULID.make()` mints the 26-char Crockford base32 string (chronologically sortable) that documents and entities key on.
 - **Enums** (`Enums.swift`) — `WorkoutStatus`, `LoadType`.
 
 ### Core Aggregates
@@ -60,7 +59,7 @@ All in `Shared/Model/`:
 - iOS 26 / watchOS 26; Swift 6 with `SWIFT_STRICT_CONCURRENCY: complete` on both targets.
 - Build number is set from the git commit count by `Scripts/update_build_number.sh` (a post-build phase); `Scripts/` also holds the App Store / TestFlight release pipeline.
 - Entitlements: iOS uses CloudDocuments + HealthKit; watch uses HealthKit only. **No CloudKit service, no App Group.**
-- SPM packages: `IndieAbout` (in-app About / changelog / license UI) and `Yams` (YAML parsing).
+- SPM packages: `IndieSync` (file-side iCloud sync core), `IndieAbout` (in-app About / changelog / license UI), and `Yams` (YAML parsing).
 
 ### Key Directories
 - `Shared/` (compiled into both targets): `Model/`, `Persistence/`, `Connectivity/`, `Utils/`, `Screenshots/`
@@ -77,12 +76,12 @@ Seeded on demand, never automatically — an empty cache at launch is indistingu
 
 ### Data Model Changes
 - A new persisted field must be added in three places: the Codable `…Document` (on-disk shape), the `@Model` cache entity, and *both directions* of the mapper in `Mappers.swift`.
-- Bump a document's `currentSchema` when its on-disk shape changes incompatibly.
+- Bump a document's `currentSchemaVersion` when its on-disk shape changes incompatibly.
 - All writes go through `SyncEngine` (`save` / `delete`) — never mutate the SwiftData cache directly, since it is rebuilt from files.
 - Mint IDs with `ULID.make()`; they are stable across cache rebuilds.
 
 ### Concurrency
-- Code is Swift 6 strict-concurrency clean. UI and orchestration types are `@MainActor`; file I/O lives in the `ICloudFileManager` actor.
+- Code is Swift 6 strict-concurrency clean. UI and orchestration types are `@MainActor`; file I/O lives in IndieSync's `DocumentFileStore` actor.
 
 ### UI
 - SwiftUI-first: `NavigationStack`, `@Query`-backed lists, form-based add/edit, sheet presentations, and swipe actions.

Shared/Connectivity/WCPayload.swift

@@ -1,3 +1,4 @@
+import IndieSync
 import Foundation
 
 /// Wire format for the iPhone↔Watch bridge. The phone is the only device that

Shared/Model/Documents.swift

@@ -1,4 +1,5 @@
 import Foundation
+import IndieSync
 
 /// On-disk JSON shape for each aggregate. Independent from the SwiftData cache
 /// entities so the wire format can evolve without dragging the cache schema.
@@ -29,7 +30,7 @@ struct SplitDocument: Codable, Sendable, Equatable, Identifiable {
     /// quarantining the user's whole routine.
     var activityType: Int?
 
-    static let currentSchema = 1
+    static let currentSchemaVersion = 1
 
     var relativePath: String { "Splits/\(id).json" }
 }
@@ -69,7 +70,7 @@ struct WorkoutDocument: Codable, Sendable, Equatable, Identifiable {
     // Bumped 1→2 when `metrics` was added: the captured HR/calorie data is
     // irreplaceable, so the forward-gate must quarantine these files on older apps
     // rather than let them strip `metrics` on rewrite.
-    static let currentSchema = 2
+    static let currentSchemaVersion = 2
 
     var relativePath: String { Self.relativePath(id: id, start: start) }
 
@@ -158,58 +159,7 @@ struct WorkoutMetrics: Codable, Sendable, Equatable {
 
 // MARK: - Forward-compatibility gate
 
-/// A file whose `schemaVersion` exceeds the reader's `currentSchema` was written
+// `VersionedDocument` (the `isReadable` quarantine gate for files written by a
-/// by a newer app version; it must be quarantined, not partially decoded (Codable
+// newer app version), `Tombstone`, and `DocumentCoder` all live in IndieSync now.
-/// silently drops unknown keys) and later rewritten — which would downgrade it
-/// and lose the newer fields.
-protocol VersionedDocument {
-    var schemaVersion: Int { get }
-    static var currentSchema: Int { get }
-}
-
 extension SplitDocument: VersionedDocument {}
 extension WorkoutDocument: VersionedDocument {}
-
-extension VersionedDocument {
-    /// True if this build can safely read (and rewrite) the document.
-    var isReadable: Bool { schemaVersion <= Self.currentSchema }
-}
-
-// MARK: - Soft-delete tombstone
-
-/// Lives at `Stubs/<id>.json` and tells every device "this aggregate has been
-/// deleted" — important when a remote device missed the `.removed` event for the
-/// live file because it was offline. After `gracePeriod` any device can prune it.
-struct Tombstone: Codable, Sendable, Equatable {
-    enum Kind: String, Codable, Sendable {
-        case split
-        case workout
-    }
-
-    var id: String                 // the aggregate's ULID
-    var kind: Kind
-    var deletedAt: Date
-
-    var relativePath: String { "Stubs/\(id).json" }
-
-    static let gracePeriod: TimeInterval = 30 * 24 * 60 * 60
-}
-
-// MARK: - JSON coding
-
-/// Shared encoder/decoder. ISO-8601 dates and sorted keys for human-readable,
-/// diff-friendly files when the container is browsed via the Files app.
-enum DocumentCoder {
-    static let encoder: JSONEncoder = {
-        let e = JSONEncoder()
-        e.outputFormatting = [.prettyPrinted, .sortedKeys]
-        e.dateEncodingStrategy = .iso8601
-        return e
-    }()
-
-    static let decoder: JSONDecoder = {
-        let d = JSONDecoder()
-        d.dateDecodingStrategy = .iso8601
-        return d
-    }()
-}

Shared/Model/Entities.swift

@@ -1,3 +1,4 @@
+import IndieSync
 import Foundation
 import SwiftData
 

Shared/Model/Mappers.swift

@@ -24,7 +24,7 @@ extension ExerciseDocument {
 
 extension SplitDocument {
     init(from split: Split) {
-        self.init(schemaVersion: Self.currentSchema, id: split.id, name: split.name,
+        self.init(schemaVersion: Self.currentSchemaVersion, id: split.id, name: split.name,
                   color: split.color, systemImage: split.systemImage, order: split.order,
                   createdAt: split.createdAt, updatedAt: split.updatedAt,
                   exercises: split.exercisesArray.map(ExerciseDocument.init(from:)),
@@ -43,7 +43,7 @@ extension WorkoutLogDocument {
 
 extension WorkoutDocument {
     init(from workout: Workout) {
-        self.init(schemaVersion: Self.currentSchema, id: workout.id, splitID: workout.splitID,
+        self.init(schemaVersion: Self.currentSchemaVersion, id: workout.id, splitID: workout.splitID,
                   splitName: workout.splitName, start: workout.start, end: workout.end,
                   status: workout.statusRaw, createdAt: workout.createdAt, updatedAt: workout.updatedAt,
                   logs: workout.logsArray.map(WorkoutLogDocument.init(from:)),

Shared/Model/ULID.swift

@@ -1,68 +1,11 @@
 import Foundation
+import IndieSync
 
-/// Minimal ULID generator.
+// The ULID implementation lives in the IndieSync package. Workouts' documents
-///
+// and cache entities key on the 26-char string form, so this shim keeps the
-/// 26-character Crockford base32 string: 10 chars of millisecond timestamp +
+// app-wide `ULID.make()` minting entry point unchanged.
-/// 16 chars of randomness. Lexicographic order matches chronological order,
+extension ULID {
-/// so workout documents sort newest-last by id and file listings stay ordered.
+    /// Mints a fresh ULID for the current instant, as its canonical
-///
+    /// 26-character Crockford base32 string.
-/// Spec: https://github.com/ulid/spec
+    static func make() -> String { ULID().stringValue }
-enum ULID {
-    /// Crockford base32 alphabet — no I, L, O, U to avoid visual confusion.
-    private static let alphabet: [Character] = Array("0123456789ABCDEFGHJKMNPQRSTVWXYZ")
-
-    /// Mints a fresh ULID for the current instant.
-    static func make() -> String {
-        let timestamp = UInt64(Date().timeIntervalSince1970 * 1000)
-        var randomness = [UInt8](repeating: 0, count: 10)
-        _ = randomness.withUnsafeMutableBytes { buffer in
-            SecRandomCopyBytes(kSecRandomDefault, buffer.count, buffer.baseAddress!)
-        }
-        return encode(timestamp: timestamp, randomness: randomness)
-    }
-
-    /// True if `s` is a 26-char ULID using the Crockford alphabet.
-    static func isValid(_ s: String) -> Bool {
-        guard s.count == 26 else { return false }
-        let allowed = Set(alphabet)
-        return s.allSatisfy { allowed.contains($0) }
-    }
-
-    /// Decodes the timestamp portion of a ULID, if valid.
-    static func timestamp(of ulid: String) -> Date? {
-        guard ulid.count == 26 else { return nil }
-        let prefix = ulid.prefix(10)
-        var value: UInt64 = 0
-        let lookup = Dictionary(uniqueKeysWithValues: alphabet.enumerated().map { ($1, UInt64($0)) })
-        for char in prefix {
-            guard let digit = lookup[char] else { return nil }
-            value = (value << 5) | digit
-        }
-        return Date(timeIntervalSince1970: Double(value) / 1000)
-    }
-
-    // MARK: - Internal
-
-    private static func encode(timestamp: UInt64, randomness: [UInt8]) -> String {
-        precondition(randomness.count == 10, "ULID randomness must be 10 bytes (80 bits)")
-        // 48-bit timestamp → 10 base32 chars (50 bits, top 2 unused).
-        var output = [Character](repeating: "0", count: 26)
-        var t = timestamp & ((1 << 48) - 1)
-        for i in stride(from: 9, through: 0, by: -1) {
-            output[i] = alphabet[Int(t & 0x1F)]
-            t >>= 5
-        }
-        // 80-bit randomness → 16 base32 chars.
-        var bigEnd = randomness
-        for i in stride(from: 25, through: 10, by: -1) {
-            var carry: UInt16 = 0
-            for j in 0..<bigEnd.count {
-                let combined = UInt16(bigEnd[j]) | (carry << 8)
-                bigEnd[j] = UInt8(combined >> 5)
-                carry = combined & 0x1F
-            }
-            output[i] = alphabet[Int(UInt8(carry))]
-        }
-        return String(output)
-    }
 }

Shared/Screenshots/ScreenshotSeed.swift

@@ -1,4 +1,5 @@
 #if DEBUG
+import IndieSync
 import Foundation
 import SwiftData
 

Workouts Watch App/Views/WorkoutLogListView.swift

@@ -5,6 +5,7 @@
 // Copyright 2025 Rouslan Zenetl. All Rights Reserved.
 //
 
+import IndieSync
 import SwiftUI
 import SwiftData
 

Workouts/Seed/SplitSeeder.swift

@@ -1,3 +1,4 @@
+import IndieSync
 import Foundation
 import SwiftData
 
@@ -58,7 +59,7 @@ enum SplitSeeder {
                 )
             }
             return SplitDocument(
-                schemaVersion: SplitDocument.currentSchema, id: ULID.make(),
+                schemaVersion: SplitDocument.currentSchemaVersion, id: ULID.make(),
                 name: split.name, color: split.color, systemImage: split.icon, order: order,
                 createdAt: Date(), updatedAt: Date(), exercises: exercises,
                 activityType: split.activity.rawValue

Workouts/Sync/ICloudFileManager.swift

@@ -1,228 +0,0 @@
-import Foundation
-
-/// All iCloud Drive file I/O, isolated to an actor so blocking `NSFileCoordinator`
-/// calls stay off the main thread. Paths are relative to the container's
-/// `Documents/` directory (e.g. `Splits/<ULID>.json`, `Stubs/<ULID>.json`).
-actor ICloudFileManager {
-    let documentsURL: URL
-
-    init(containerURL: URL) {
-        self.documentsURL = containerURL.appendingPathComponent("Documents", isDirectory: true)
-    }
-
-    /// Create the directory skeleton. Actor-isolated (NOT in init) so the
-    /// potentially-blocking file touch runs on the actor's executor, never main.
-    func prepareDirectories() {
-        for sub in ["Splits", "Workouts", "Stubs"] {
-            let url = documentsURL.appendingPathComponent(sub, isDirectory: true)
-            try? FileManager.default.createDirectory(at: url, withIntermediateDirectories: true)
-        }
-    }
-
-    // MARK: - Coordinated primitives
-
-    func write(_ data: Data, to relativePath: String) throws {
-        let fileURL = documentsURL.appendingPathComponent(relativePath)
-        try FileManager.default.createDirectory(at: fileURL.deletingLastPathComponent(),
-                                                withIntermediateDirectories: true)
-        var coordError: NSError?
-        var writeError: Error?
-        NSFileCoordinator().coordinate(writingItemAt: fileURL, options: .forReplacing, error: &coordError) { url in
-            do { try data.write(to: url, options: .atomic) }
-            catch { writeError = error }
-        }
-        if let error = coordError ?? writeError { throw error }
-    }
-
-    /// Eviction-safe, conflict-safe read: resolves any iCloud conflict versions,
-    /// materializes an evicted file (bounded wait), then does the coordinated
-    /// read — so callers never decode a dataless placeholder or a stale conflict
-    /// sibling. Throws on download timeout rather than skipping — a silently
-    /// dropped evicted file looks to the user like the record was deleted.
-    func read(relativePath: String) async throws -> Data {
-        resolveConflictsIfAny(at: documentsURL.appendingPathComponent(relativePath))
-        try await ensureDownloaded(relativePath: relativePath)
-        let fileURL = documentsURL.appendingPathComponent(relativePath)
-        var coordError: NSError?
-        var result: Result<Data, Error>?
-        NSFileCoordinator().coordinate(readingItemAt: fileURL, options: [], error: &coordError) { url in
-            do { result = .success(try Data(contentsOf: url)) }
-            catch { result = .failure(error) }
-        }
-        if let coordError { throw coordError }
-        switch result {
-        case .success(let data): return data
-        case .failure(let error): throw error
-        case .none: throw CocoaError(.fileReadUnknown)
-        }
-    }
-
-    func remove(relativePath: String) throws {
-        let fileURL = documentsURL.appendingPathComponent(relativePath)
-        guard FileManager.default.fileExists(atPath: fileURL.path) else { return }
-        var coordError: NSError?
-        var deleteError: Error?
-        NSFileCoordinator().coordinate(writingItemAt: fileURL, options: .forDeleting, error: &coordError) { url in
-            do { try FileManager.default.removeItem(at: url) }
-            catch { deleteError = error }
-        }
-        if let error = coordError ?? deleteError { throw error }
-    }
-
-    func fileExists(_ relativePath: String) -> Bool {
-        FileManager.default.fileExists(atPath: documentsURL.appendingPathComponent(relativePath).path)
-    }
-
-    // MARK: - Soft delete
-
-    /// Writes a tombstone stub then removes the live file. Other devices learn of
-    /// the delete via the stub even if they were offline for the file removal.
-    func writeTombstoneAndRemove(_ tombstone: Tombstone, livePath: String) throws {
-        let data = try DocumentCoder.encoder.encode(tombstone)
-        try write(data, to: tombstone.relativePath)
-        try remove(relativePath: livePath)
-    }
-
-    // MARK: - Enumeration
-
-    /// Relative paths of all live data files (`Splits/…`, `Workouts/…`), excluding `Stubs/`.
-    func listDataFiles() -> [String] {
-        listJSON().filter { !$0.hasPrefix("Stubs/") }
-    }
-
-    /// All tombstones currently on disk (evicted stubs are downloaded first —
-    /// old stubs are routinely evicted, and cleanup needs their `deletedAt`).
-    func listTombstones() async -> [Tombstone] {
-        var tombstones: [Tombstone] = []
-        for path in listJSON() where path.hasPrefix("Stubs/") {
-            guard let data = try? await read(relativePath: path) else { continue }
-            if let tombstone = try? DocumentCoder.decoder.decode(Tombstone.self, from: data) {
-                tombstones.append(tombstone)
-            }
-        }
-        return tombstones
-    }
-
-    /// IDs of all tombstones, derived from stub filenames alone. Unlike
-    /// `listTombstones()` this needs no reads, so an evicted stub still counts —
-    /// reconcile must never treat a record as live because its stub happened to
-    /// be evicted.
-    func listTombstoneIDs() -> Set<String> {
-        Set(listJSON().filter { $0.hasPrefix("Stubs/") }
-            .map { ($0 as NSString).lastPathComponent.replacingOccurrences(of: ".json", with: "") })
-    }
-
-    /// Whether a deletion stub exists for an id — placeholder-aware, so an
-    /// evicted stub still vetoes a resurrecting live file.
-    func stubExists(id: String) -> Bool {
-        let stubs = documentsURL.appendingPathComponent("Stubs", isDirectory: true)
-        return FileManager.default.fileExists(atPath: stubs.appendingPathComponent("\(id).json").path)
-            || FileManager.default.fileExists(atPath: stubs.appendingPathComponent(".\(id).json.icloud").path)
-    }
-
-    /// Deliberately does NOT pass `.skipsHiddenFiles`: iOS materializes evicted
-    /// iCloud files as hidden placeholder dotfiles (`.<name>.json.icloud`), and
-    /// skipping hidden files would drop every evicted record from the listing —
-    /// reconcile would then prune their cache entities as "file gone".
-    /// Placeholder names are mapped back to their real `<name>.json`.
-    private func listJSON() -> [String] {
-        let base = documentsURL.path + "/"
-        guard let enumerator = FileManager.default.enumerator(
-            at: documentsURL,
-            includingPropertiesForKeys: nil,
-            options: []
-        ) else { return [] }
-        var seen: Set<String> = []
-        var paths: [String] = []
-        for case let url as URL in enumerator {
-            let full = url.path
-            guard full.hasPrefix(base) else { continue }
-            guard let real = Self.realRelativePath(fromRaw: String(full.dropFirst(base.count))),
-                  seen.insert(real).inserted else { continue }
-            paths.append(real)
-        }
-        return paths
-    }
-
-    /// Map a raw relative path from the enumerator — which may be an eviction
-    /// placeholder like `Workouts/2026/03/.<ULID>.json.icloud` — to the real
-    /// path `Workouts/2026/03/<ULID>.json`. Returns nil for non-JSON entries.
-    nonisolated static func realRelativePath(fromRaw raw: String) -> String? {
-        var components = raw.split(separator: "/", omittingEmptySubsequences: true).map(String.init)
-        guard var name = components.popLast() else { return nil }
-        if name.hasPrefix("."), name.hasSuffix(".icloud") {
-            name = String(name.dropFirst().dropLast(".icloud".count))
-        }
-        guard name.hasSuffix(".json") else { return nil }
-        components.append(name)
-        return components.joined(separator: "/")
-    }
-
-    // MARK: - Conflict resolution
-
-    /// If iCloud Drive created conflict versions (concurrent writes from
-    /// different devices), pick whichever has the latest modification date,
-    /// promote it to the canonical file, and mark every conflict resolved.
-    /// Whole-file last-writer-wins by mod-date — honest for one-file-per-record
-    /// data. Left unresolved, conflict siblings accumulate silently and a
-    /// coordinated read returns whichever version the filesystem hands back.
-    private func resolveConflictsIfAny(at fileURL: URL) {
-        let conflicts = NSFileVersion.unresolvedConflictVersionsOfItem(at: fileURL) ?? []
-        guard !conflicts.isEmpty else { return }
-
-        let currentDate = NSFileVersion.currentVersionOfItem(at: fileURL)?.modificationDate ?? .distantPast
-        var winnerDate = currentDate
-        var winnerVersion: NSFileVersion?
-
-        for version in conflicts {
-            if let date = version.modificationDate, date > winnerDate {
-                winnerDate = date
-                winnerVersion = version
-            }
-        }
-
-        // Promote the winner and prune the losers inside a coordinated write —
-        // these are real file mutations (replaceItem / removeOtherVersions) and
-        // must not race a concurrent write or the iCloud daemon; NSFileVersion
-        // does not coordinate internally.
-        var coordError: NSError?
-        NSFileCoordinator().coordinate(writingItemAt: fileURL, options: .forReplacing, error: &coordError) { url in
-            if let winner = winnerVersion {
-                do {
-                    try winner.replaceItem(at: url, options: [])
-                } catch {
-                    print("[Sync] Conflict promotion failed for \(url.lastPathComponent): \(error)")
-                }
-            }
-            for version in conflicts {
-                version.isResolved = true
-            }
-            try? NSFileVersion.removeOtherVersionsOfItem(at: url)
-        }
-        if let coordError {
-            print("[Sync] Conflict coordination failed for \(fileURL.lastPathComponent): \(coordError)")
-        }
-    }
-
-    // MARK: - Eviction
-
-    /// Triggers a download for an evicted file and polls until it materializes.
-    /// `startDownloadingUbiquitousItem` is fire-and-forget with no completion
-    /// callback, so a bounded poll (30s) is the only way to wait; on timeout this
-    /// throws rather than letting the caller read a placeholder.
-    func ensureDownloaded(relativePath: String) async throws {
-        let fileURL = documentsURL.appendingPathComponent(relativePath)
-        let values = try fileURL.resourceValues(forKeys: [.ubiquitousItemDownloadingStatusKey])
-        guard let status = values.ubiquitousItemDownloadingStatus, status != .current else { return }
-
-        try FileManager.default.startDownloadingUbiquitousItem(at: fileURL)
-        for _ in 0..<60 {
-            try await Task.sleep(for: .milliseconds(500))
-            let updated = try fileURL.resourceValues(forKeys: [.ubiquitousItemDownloadingStatusKey])
-            if let s = updated.ubiquitousItemDownloadingStatus, s == .current { return }
-        }
-        throw CocoaError(.fileReadNoPermission, userInfo: [
-            NSLocalizedDescriptionKey: "Timed out downloading \(relativePath) from iCloud"
-        ])
-    }
-}

Workouts/Sync/ICloudFileMonitor.swift

@@ -1,111 +0,0 @@
-import Foundation
-
-/// Wraps a single `NSMetadataQuery` over the container's `Documents/` scope and
-/// emits add/modify/remove events (paths relative to `Documents/`) via an
-/// `AsyncStream`. `@MainActor` because `NSMetadataQuery` posts on, and must be
-/// driven from, the main thread.
-@MainActor
-final class ICloudFileMonitor {
-    enum FileChangeEvent: Sendable {
-        case added(relativePath: String)
-        case modified(relativePath: String)
-        case removed(relativePath: String)
-    }
-
-    private let documentsURL: URL
-    private var query: NSMetadataQuery?
-    private var knownFiles: Set<String> = []
-    private var continuation: AsyncStream<FileChangeEvent>.Continuation?
-
-    init(documentsURL: URL) {
-        self.documentsURL = documentsURL
-    }
-
-    func events() -> AsyncStream<FileChangeEvent> {
-        AsyncStream { continuation in
-            self.continuation = continuation
-            continuation.onTermination = { @Sendable _ in
-                Task { @MainActor in self.stop() }
-            }
-        }
-    }
-
-    func start() {
-        let query = NSMetadataQuery()
-        query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope]
-        query.predicate = NSPredicate(format: "%K LIKE '*.json'", NSMetadataItemFSNameKey)
-        self.query = query
-
-        NotificationCenter.default.addObserver(
-            self, selector: #selector(queryDidFinishGathering(_:)),
-            name: .NSMetadataQueryDidFinishGathering, object: query)
-        NotificationCenter.default.addObserver(
-            self, selector: #selector(queryDidUpdate(_:)),
-            name: .NSMetadataQueryDidUpdate, object: query)
-
-        query.start()
-    }
-
-    func stop() {
-        query?.stop()
-        if let query { NotificationCenter.default.removeObserver(self, name: nil, object: query) }
-        query = nil
-    }
-
-    // MARK: - Notifications
-
-    @objc private func queryDidFinishGathering(_ notification: Notification) {
-        query?.disableUpdates()
-        defer { query?.enableUpdates() }
-        // Seed the baseline only; do NOT emit (else every existing file would fire
-        // `.added` on each launch). The engine's connect-time `reconcile()` does the
-        // initial import; this query then reports only live deltas after the baseline.
-        knownFiles = Set(currentRelativePaths())
-    }
-
-    @objc private func queryDidUpdate(_ notification: Notification) {
-        query?.disableUpdates()
-        defer { query?.enableUpdates() }
-
-        let currentFiles = Set(currentRelativePaths())
-
-        for file in currentFiles.subtracting(knownFiles) {
-            continuation?.yield(.added(relativePath: file))
-        }
-        for file in knownFiles.subtracting(currentFiles) {
-            continuation?.yield(.removed(relativePath: file))
-        }
-        if let updated = notification.userInfo?[NSMetadataQueryUpdateChangedItemsKey] as? [NSMetadataItem] {
-            for item in updated {
-                if let url = item.value(forAttribute: NSMetadataItemURLKey) as? URL,
-                   let path = relativePath(from: url), knownFiles.contains(path) {
-                    continuation?.yield(.modified(relativePath: path))
-                }
-            }
-        }
-        knownFiles = currentFiles
-    }
-
-    // MARK: - Helpers
-
-    private func currentRelativePaths() -> [String] {
-        guard let query else { return [] }
-        var paths: [String] = []
-        for i in 0..<query.resultCount {
-            if let item = query.result(at: i) as? NSMetadataItem,
-               let url = item.value(forAttribute: NSMetadataItemURLKey) as? URL,
-               let path = relativePath(from: url) {
-                paths.append(path)
-            }
-        }
-        return paths
-    }
-
-    private func relativePath(from url: URL) -> String? {
-        let base = documentsURL.path + "/"
-        let full = url.path
-        guard full.hasPrefix(base) else { return nil }
-        let relative = String(full.dropFirst(base.count))
-        return relative.hasSuffix(".json") ? relative : nil
-    }
-}

Workouts/Sync/SyncEngine.swift

@@ -1,4 +1,5 @@
 import Foundation
+import IndieSync
 import SwiftData
 import Observation
 import os
@@ -38,8 +39,9 @@ final class SyncEngine {
 
     private let log = Logger(subsystem: "dev.rzen.indie.Workouts", category: "sync")
     private let modelContainer: ModelContainer
-    private var fileManager: ICloudFileManager?
+    private var store: DocumentFileStore?
-    private var monitor: ICloudFileMonitor?
+    private var tombstones: TombstoneStore?
+    private var monitor: MetadataObserver?
     private var monitorTask: Task<Void, Never>?
     private var connectAttempt = 0
 
@@ -107,7 +109,7 @@ final class SyncEngine {
         guard let containerURL = resolved else { return }
         log.info("connect[\(attempt)]: container URL = \(containerURL.path, privacy: .public)")
 
-        let fm = ICloudFileManager(containerURL: containerURL)
+        let store = DocumentFileStore(root: containerURL.appendingPathComponent("Documents", isDirectory: true))
 
         // Safety net only: prepareDirectories is a local op that effectively never
         // blocks, but if the first container file op ever wedges we don't want an
@@ -121,17 +123,18 @@ final class SyncEngine {
             }
         }
         log.info("connect[\(attempt)]: preparing directories…")
-        await fm.prepareDirectories()
+        await store.prepareDirectories(["Splits", "Workouts", "Stubs"])
         safety.cancel()
         guard attempt == connectAttempt else { return }
 
-        self.fileManager = fm
+        self.store = store
+        self.tombstones = TombstoneStore(store: store)
         iCloudStatus = .available
         log.info("connect[\(attempt)]: directories ready → available")
         WorkoutsModelContainer.persistCurrentIdentityToken()
 
         await reconcile()
-        startMonitoring(documentsURL: fm.documentsURL)
+        startMonitoring(documentsURL: store.rootURL)
         cleanupOldStubs()
     }
 
@@ -149,17 +152,18 @@ final class SyncEngine {
 
     private func startMonitoring(documentsURL: URL) {
         monitorTask?.cancel()
-        let monitor = ICloudFileMonitor(documentsURL: documentsURL)
+        let monitor = MetadataObserver(documentsURL: documentsURL)
         self.monitor = monitor
         monitor.start()
         monitorTask = Task { [weak self] in
-            for await event in monitor.events() {
+            for await batch in monitor.events() {
-                await self?.handle(event)
+                await self?.handle(batch)
             }
         }
     }
 
-    private func handle(_ event: ICloudFileMonitor.FileChangeEvent) async {
+    private func handle(_ batch: [FileChangeEvent]) async {
+        for event in batch {
             switch event {
             case .added(let path), .modified(let path):
                 if path.hasPrefix("Stubs/") {
@@ -172,6 +176,7 @@ final class SyncEngine {
                     deleteCachedEntity(jsonRelativePath: path)
                 }
             }
+        }
         do { try context.save() } catch { report("Cache save failed", error) }
         onCacheChanged?()
     }
@@ -195,9 +200,9 @@ final class SyncEngine {
     // MARK: - Public CRUD (write path: files only)
 
     func save(split doc: SplitDocument) async {
-        guard let fm = fileManager else { return }
+        guard let store else { return }
         do {
-            try await fm.write(try DocumentCoder.encoder.encode(doc), to: doc.relativePath)
+            try await store.write(doc, to: doc.relativePath)
             lastSyncError = nil
         } catch {
             report("Failed to save split", error)
@@ -206,9 +211,9 @@ final class SyncEngine {
     }
 
     func save(workout doc: WorkoutDocument) async {
-        guard let fm = fileManager else { return }
+        guard let store else { return }
         do {
-            try await fm.write(try DocumentCoder.encoder.encode(doc), to: doc.relativePath)
+            try await store.write(doc, to: doc.relativePath)
             lastSyncError = nil
         } catch {
             report("Failed to save workout", error)
@@ -220,18 +225,20 @@ final class SyncEngine {
     }
 
     func delete(split: Split) async {
-        await softDelete(id: split.id, kind: .split, livePath: split.jsonRelativePath)
+        await softDelete(id: split.id, kind: "split", livePath: split.jsonRelativePath)
     }
 
     func delete(workout: Workout) async {
-        await softDelete(id: workout.id, kind: .workout, livePath: workout.jsonRelativePath)
+        await softDelete(id: workout.id, kind: "workout", livePath: workout.jsonRelativePath)
     }
 
-    private func softDelete(id: String, kind: Tombstone.Kind, livePath: String) async {
+    /// Writes a tombstone stub then removes the live file. Other devices learn of
-        guard let fm = fileManager else { return }
+    /// the delete via the stub even if they were offline for the file removal.
-        let tombstone = Tombstone(id: id, kind: kind, deletedAt: Date())
+    private func softDelete(id: String, kind: String, livePath: String) async {
+        guard let store, let tombstones else { return }
         do {
-            try await fm.writeTombstoneAndRemove(tombstone, livePath: livePath)
+            try await tombstones.writeTombstone(Tombstone(id: id, deletedAt: Date(), kind: kind))
+            try await store.remove(at: livePath)
             lastSyncError = nil
         } catch {
             report("Failed to delete \(id)", error)
@@ -241,10 +248,10 @@ final class SyncEngine {
     // MARK: - Import / reconcile
 
     private func importFile(relativePath: String) async {
-        guard let fm = fileManager else { return }
+        guard let store, let tombstones else { return }
         let data: Data
         do {
-            data = try await fm.read(relativePath: relativePath)
+            data = try await store.readData(from: relativePath)
         } catch {
             // Includes eviction-download timeouts — log loudly, never silently
             // treat an unreadable file as absent. The next monitor event or
@@ -255,12 +262,12 @@ final class SyncEngine {
         }
 
         if relativePath.hasPrefix("Splits/") {
-            guard let doc = try? DocumentCoder.decoder.decode(SplitDocument.self, from: data), doc.isReadable else { return }
+            guard let doc = try? DocumentCoder.decode(SplitDocument.self, from: data), doc.isReadable else { return }
-            if await fm.stubExists(id: doc.id) { try? await fm.remove(relativePath: relativePath); return }
+            if await tombstones.stubExists(id: doc.id) { try? await store.remove(at: relativePath); return }
             CacheMapper.upsertSplit(doc, relativePath: relativePath, into: context)
         } else if relativePath.hasPrefix("Workouts/") {
-            guard let doc = try? DocumentCoder.decoder.decode(WorkoutDocument.self, from: data), doc.isReadable else { return }
+            guard let doc = try? DocumentCoder.decode(WorkoutDocument.self, from: data), doc.isReadable else { return }
-            if await fm.stubExists(id: doc.id) { try? await fm.remove(relativePath: relativePath); return }
+            if await tombstones.stubExists(id: doc.id) { try? await store.remove(at: relativePath); return }
             CacheMapper.upsertWorkout(doc, relativePath: relativePath, into: context)
         }
     }
@@ -269,14 +276,14 @@ final class SyncEngine {
     /// prunes entities whose file is gone or tombstoned. Runs on connect so
     /// changes accumulated while the app was closed are picked up.
     private func reconcile() async {
-        guard let fm = fileManager else { return }
+        guard let store, let tombstones else { return }
         isSyncing = true
         defer { isSyncing = false }
 
         // IDs from stub filenames, not stub contents — an evicted stub must
         // still count as a tombstone or the deleted record resurrects.
-        let tombstoned = await fm.listTombstoneIDs()
+        let tombstoned = await tombstones.listStubIDs()
-        let dataFiles = await fm.listDataFiles()
+        let dataFiles = await store.list().filter { !$0.hasPrefix("Stubs/") }
 
         var liveSplitIDs = Set<String>()
         var liveWorkoutIDs = Set<String>()
@@ -285,7 +292,7 @@ final class SyncEngine {
         for path in dataFiles {
             let data: Data
             do {
-                data = try await fm.read(relativePath: path)
+                data = try await store.readData(from: path)
             } catch {
                 // A failed read (eviction-download timeout, coordination error)
                 // is not proof the record is gone — remember the path so the
@@ -298,13 +305,13 @@ final class SyncEngine {
                 continue
             }
             if path.hasPrefix("Splits/") {
-                guard let doc = try? DocumentCoder.decoder.decode(SplitDocument.self, from: data), doc.isReadable else { continue }
+                guard let doc = try? DocumentCoder.decode(SplitDocument.self, from: data), doc.isReadable else { continue }
-                if tombstoned.contains(doc.id) { try? await fm.remove(relativePath: path); continue }
+                if tombstoned.contains(doc.id) { try? await store.remove(at: path); continue }
                 CacheMapper.upsertSplit(doc, relativePath: path, into: context)
                 liveSplitIDs.insert(doc.id)
             } else if path.hasPrefix("Workouts/") {
-                guard let doc = try? DocumentCoder.decoder.decode(WorkoutDocument.self, from: data), doc.isReadable else { continue }
+                guard let doc = try? DocumentCoder.decode(WorkoutDocument.self, from: data), doc.isReadable else { continue }
-                if tombstoned.contains(doc.id) { try? await fm.remove(relativePath: path); continue }
+                if tombstoned.contains(doc.id) { try? await store.remove(at: path); continue }
                 CacheMapper.upsertWorkout(doc, relativePath: path, into: context)
                 liveWorkoutIDs.insert(doc.id)
             }
@@ -357,12 +364,11 @@ final class SyncEngine {
     // MARK: - Maintenance
 
     private func cleanupOldStubs() {
-        guard let fm = fileManager else { return }
+        guard let tombstones else { return }
         Task.detached(priority: .utility) {
-            let cutoff = Date().addingTimeInterval(-Tombstone.gracePeriod)
+            // Downloads evicted stubs to read their deletedAt, prunes past the
-            for tombstone in await fm.listTombstones() where tombstone.deletedAt < cutoff {
+            // 30-day grace period.
-                try? await fm.remove(relativePath: tombstone.relativePath)
+            try? await tombstones.prune()
-            }
         }
     }
 

Workouts/Views/Exercises/ExerciseListView.swift

@@ -7,6 +7,7 @@
 // Copyright 2025 Rouslan Zenetl. All Rights Reserved.
 //
 
+import IndieSync
 import SwiftUI
 import SwiftData
 
@@ -207,7 +208,7 @@ struct ExerciseListView: View {
             )
         }
         let doc = WorkoutDocument(
-            schemaVersion: WorkoutDocument.currentSchema,
+            schemaVersion: WorkoutDocument.currentSchemaVersion,
             id: ULID.make(),
             splitID: split.id,
             splitName: split.name,

Workouts/Views/Splits/SplitAddEditView.swift

@@ -7,6 +7,7 @@
 // Copyright 2025 Rouslan Zenetl. All Rights Reserved.
 //
 
+import IndieSync
 import SwiftUI
 import SwiftData
 
@@ -157,7 +158,7 @@ struct SplitAddEditView: View {
             // Create new split
             let existing = (try? modelContext.fetch(FetchDescriptor<Split>())) ?? []
             let doc = SplitDocument(
-                schemaVersion: SplitDocument.currentSchema,
+                schemaVersion: SplitDocument.currentSchemaVersion,
                 id: ULID.make(),
                 name: name,
                 color: color,

Workouts/Views/Splits/SplitDetailView.swift

@@ -7,6 +7,7 @@
 // Copyright 2025 Rouslan Zenetl. All Rights Reserved.
 //
 
+import IndieSync
 import SwiftUI
 import SwiftData
 

Workouts/Views/WorkoutLogs/WorkoutLogListView.swift

@@ -7,6 +7,7 @@
 // Copyright 2025 Rouslan Zenetl. All Rights Reserved.
 //
 
+import IndieSync
 import SwiftUI
 import SwiftData
 

Workouts/Views/WorkoutLogs/WorkoutLogsView.swift

@@ -7,6 +7,7 @@
 // Copyright 2025 Rouslan Zenetl. All Rights Reserved.
 //
 
+import IndieSync
 import SwiftUI
 import SwiftData
 
@@ -238,7 +239,7 @@ struct SplitPickerSheet: View {
 
         // A freshly started workout has no `end` — only completion stamps it.
         let doc = WorkoutDocument(
-            schemaVersion: WorkoutDocument.currentSchema,
+            schemaVersion: WorkoutDocument.currentSchemaVersion,
             id: ULID.make(),
             splitID: split.id,
             splitName: split.name,

project.yml

@@ -19,6 +19,9 @@ packages:
   IndieAbout:
     url: https://git.rzen.dev/rzen/indie-about.git
     from: "0.2.2"
+  IndieSync:
+    url: https://git.rzen.dev/rzen/indie-sync.git
+    from: "0.1.0"
   Yams:
     url: https://github.com/jpsim/Yams
     from: "6.0.0"
@@ -45,6 +48,7 @@ targets:
         type: file
     dependencies:
       - package: IndieAbout
+      - package: IndieSync
       - package: Yams
       - target: Workouts Watch App
     postBuildScripts:
@@ -81,6 +85,7 @@ targets:
           - "Resources/Info-*.plist"
           - "Resources/*.entitlements"
     dependencies:
+      - package: IndieSync
       - target: Workouts Watch Widget
         embed: true
     postBuildScripts: