Restructure into a three-tab app with Progress, goals, and Meditation

The UX redesign's first landing (spec in UX-REDESIGN.md): ContentView
becomes a Today / Progress / Settings TabView, "Routine" replaces
"Split" in every user-facing string and view name (code-level types
keep their names), and workout starting moves to shared
WorkoutStarter / StartedWorkoutNavigator plumbing.

- New Progress tab: weekly goal streaks, workout trends, per-exercise
  weight progression, achievements, and the full history list
  (WorkoutLogsView -> WorkoutHistoryView).
- Goals: stable categories workouts roll up to, managed from Settings.
- New Meditation exercise + starter routine; timed sits record to
  Apple Health as Mind & Body sessions.

Claude-Session: https://claude.ai/code/session_012qw2itfzKyEJ1HpsFt8Ex4

Shared/Model/Documents.swift

@@ -5,16 +5,16 @@ import IndieSync
 /// entities so the wire format can evolve without dragging the cache schema.
 ///
 /// One document = one aggregate root:
-///   • `SplitDocument`   embeds its `[ExerciseDocument]`   → `Splits/<ULID>.json`
+///   • `RoutineDocument` embeds its `[ExerciseDocument]`   → `Splits/<ULID>.json`
 ///   • `WorkoutDocument` embeds its `[WorkoutLogDocument]` → `Workouts/YYYY/MM/<ULID>.json`
 ///
 /// `schemaVersion` lets us migrate old files on read without forcing a rewrite
 /// at sync time, and forward-gates files written by a newer app version.
 /// These documents are also the wire format for the iPhone↔Watch bridge.
 
-// MARK: - Split
+// MARK: - Routine
 
-struct SplitDocument: Codable, Sendable, Equatable, Identifiable {
+struct RoutineDocument: Codable, Sendable, Equatable, Identifiable {
     var schemaVersion: Int
     var id: String                 // ULID
     var name: String
@@ -29,7 +29,7 @@ struct SplitDocument: Codable, Sendable, Equatable, Identifiable {
     /// older app dropping it on rewrite (reverting to the default) is preferable to
     /// quarantining the user's whole routine.
     var activityType: Int?
-    /// Per-split rest length (seconds) and flow-mode toggle. Both optional and
+    /// Per-routine rest length (seconds) and flow-mode toggle. Both optional and
     /// deliberately NOT schema-bumped, same rationale as `activityType`: an older
     /// app dropping them on rewrite reverts to the global default rest / no-flow,
     /// which is preferable to quarantining the user's whole routine.
@@ -46,6 +46,9 @@ struct SplitDocument: Codable, Sendable, Equatable, Identifiable {
     // quarantine rather than rewrite.
     static let currentSchemaVersion = 3
 
+    // PINNED: the iCloud directory name stays "Splits/" even though the type is now
+    // `RoutineDocument`. Existing user files live under Splits/ — the directory name
+    // is on-disk data, not a symbol, and must not change on the rename.
     var relativePath: String { "Splits/\(id).json" }
 }
 
@@ -87,8 +90,8 @@ struct SetEntry: Codable, Sendable, Equatable {
 struct WorkoutDocument: Codable, Sendable, Equatable, Identifiable {
     var schemaVersion: Int
     var id: String                 // ULID (chronological)
-    var splitID: String?
-    var splitName: String?
+    var routineID: String?
+    var routineName: String?
     var start: Date
     var end: Date?
     var status: String             // WorkoutStatus raw value
@@ -109,13 +112,35 @@ struct WorkoutDocument: Codable, Sendable, Equatable, Identifiable {
     /// period. See `WorkoutMergePlanner`.
     var deletedLogIDs: [String: Date]? = nil
 
-    /// Snapshot of the split's rest length / flow flag at plan time (a running
-    /// workout has no live link to its split, same reason sets/reps/weight are
+    /// Snapshot of the routine's rest length / flow flag at plan time (a running
+    /// workout has no live link to its routine, same reason sets/reps/weight are
     /// snapshotted per log). Optional and not schema-bumped, same rationale as
-    /// `SplitDocument.restSeconds`/`autoAdvance`.
+    /// `RoutineDocument.restSeconds`/`autoAdvance`.
     var restSeconds: Int? = nil
     var autoAdvance: Bool? = nil
 
+    // PINNED CODING KEYS: the Swift properties `routineID`/`routineName` were renamed
+    // from `splitID`/`splitName`, but their on-disk (and iPhone↔Watch wire) JSON keys
+    // stay `"splitID"`/`"splitName"` so existing files and a not-yet-updated peer still
+    // decode. Every stored property must be enumerated here (the computed `relativePath`
+    // and static members are not coded); all others keep their default key names.
+    enum CodingKeys: String, CodingKey {
+        case schemaVersion
+        case id
+        case routineID = "splitID"
+        case routineName = "splitName"
+        case start
+        case end
+        case status
+        case createdAt
+        case updatedAt
+        case logs
+        case metrics
+        case deletedLogIDs
+        case restSeconds
+        case autoAdvance
+    }
+
     // 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.
@@ -180,7 +205,7 @@ extension WorkoutDocument {
     /// End the workout now, keeping progress: mark every not-completed log as skipped, then
     /// recompute so it resolves to `.completed` (with `end` stamped). This is the
     /// "End Workout → Save" operation, shared by the in-workout menu and the
-    /// start-a-new-split prompt.
+    /// start-a-new-routine prompt.
     mutating func endKeepingProgress() {
         for i in logs.indices where (WorkoutStatus(rawValue: logs[i].status) ?? .notStarted) != .completed {
             logs[i].transition(to: .skipped)
@@ -222,7 +247,7 @@ struct WorkoutLogDocument: Codable, Sendable, Equatable, Identifiable {
 }
 
 extension WorkoutLogDocument {
-    /// Build a fresh plan-time log from a split's exercise. Snapshots the plan
+    /// Build a fresh plan-time log from a routine's exercise. Snapshots the plan
     /// fields (sets/reps/weight/duration) *and* the machine comfort settings, so a
     /// running workout carries the exercise's settings as its own editable copy —
     /// `nil` stays `nil` (not a machine exercise), and `[]` stays `[]` (machine
@@ -337,9 +362,48 @@ struct WorkoutMetrics: Codable, Sendable, Equatable {
     var recordedAt: Date
 }
 
+// MARK: - Schedule
+
+/// The plan layer: one routine + a recurrence + an optional goal tag, persisted as
+/// `Schedules/<ULID>.json`. The schedule is the join object between routines and
+/// goals — scheduling never touches the routine file (starter routines are
+/// immutable fixed-ULID seeds).
+struct ScheduleDocument: Codable, Sendable, Equatable, Identifiable {
+    var schemaVersion: Int
+    var id: String            // ULID
+    var routineID: String
+    var routineName: String   // denormalized display fallback (routine may be deleted)
+    var goal: String?         // GoalKind raw value; nil = unassigned
+    var recurrence: String    // ScheduleRecurrence raw value
+    var weekdays: [Int]?      // Calendar weekday numbers 1 (Sun) – 7 (Sat); .fixedDays only
+    var timesPerWeek: Int?    // .frequency only
+    var date: Date? = nil     // the one-off day; .once only
+    var order: Int
+    var createdAt: Date
+    var updatedAt: Date
+
+    static let currentSchemaVersion = 1
+
+    var relativePath: String { "Schedules/\(id).json" }
+}
+
+extension ScheduleDocument {
+    /// The tagged goal, or nil when unassigned / an unknown raw value.
+    var goalKind: GoalKind? { goal.flatMap(GoalKind.init(rawValue:)) }
+
+    /// The recurrence, defaulting to `.daily` on an unknown raw value.
+    var recurrenceEnum: ScheduleRecurrence { ScheduleRecurrence(rawValue: recurrence) ?? .daily }
+
+    /// Human-readable recurrence line ("Jul 12, 2026" / "Daily" / "Mon & Thu" / "2× per week").
+    var recurrenceSummary: String {
+        recurrenceEnum.summary(weekdays: weekdays, timesPerWeek: timesPerWeek, date: date)
+    }
+}
+
 // MARK: - Forward-compatibility gate
 
 // `VersionedDocument` (the `isReadable` quarantine gate for files written by a
 // newer app version), `Tombstone`, and `DocumentCoder` all live in IndieSync now.
-extension SplitDocument: VersionedDocument {}
+extension RoutineDocument: VersionedDocument {}
 extension WorkoutDocument: VersionedDocument {}
+extension ScheduleDocument: VersionedDocument {}