Add the exercise reference library, animated exercise figures, and exercise categories

Exercise Library/ holds per-exercise reference docs (setup, cues,
mistakes, progressions) with SVG visuals and a Python-rendered motion
pipeline; Workouts/ExerciseFigure renders the bundled *.motion.json
rigs as animated stick figures on the exercise screen. Exercises gain
a warm-up/main-circuit category, timed exercises display hold time via
planSummary, and a completed exercise reopens to a check screen instead
of its timers.

Shared/Model/Documents.swift

@@ -46,6 +46,10 @@ struct ExerciseDocument: Codable, Sendable, Equatable, Identifiable {
     var durationSeconds: Int       // total seconds (0 when not a timed exercise)
     var weightLastUpdated: Date?
     var weightReminderWeeks: Int
+    /// Raw `ExerciseCategory`; nil → main circuit. Like `activityType`, deliberately
+    /// NOT schema-bumped: it only affects how the split screen groups its list, so an
+    /// older app dropping it on rewrite beats quarantining the routine.
+    var category: Int?
 }
 
 // MARK: - Workout

Shared/Model/Entities.swift

@@ -64,12 +64,13 @@ final class Exercise {
     var durationTotalSeconds: Int = 0
     var weightLastUpdated: Date?
     var weightReminderTimeIntervalWeeks: Int = 2
+    var categoryRaw: Int = ExerciseCategory.main.rawValue
 
     var split: Split?
 
     init(id: String, name: String, order: Int, sets: Int, reps: Int, weight: Int,
          loadType: Int, durationTotalSeconds: Int, weightLastUpdated: Date?,
-         weightReminderTimeIntervalWeeks: Int) {
+         weightReminderTimeIntervalWeeks: Int, categoryRaw: Int = ExerciseCategory.main.rawValue) {
         self.id = id
         self.name = name
         self.order = order
@@ -80,6 +81,7 @@ final class Exercise {
         self.durationTotalSeconds = durationTotalSeconds
         self.weightLastUpdated = weightLastUpdated
         self.weightReminderTimeIntervalWeeks = weightReminderTimeIntervalWeeks
+        self.categoryRaw = categoryRaw
     }
 
     var loadTypeEnum: LoadType {
@@ -87,6 +89,27 @@ final class Exercise {
         set { loadType = newValue.rawValue }
     }
 
+    var categoryEnum: ExerciseCategory {
+        get { ExerciseCategory(rawValue: categoryRaw) ?? .main }
+        set { categoryRaw = newValue.rawValue }
+    }
+
+    /// One-line plan summary for list rows — duration exercises show their hold time
+    /// ("3 × 45 sec"), unloaded ones drop the weight ("3 × 12 reps"), weighted ones
+    /// keep the full "3 × 10 × 40 lb".
+    func planSummary(weightUnit: WeightUnit) -> String {
+        switch loadTypeEnum {
+        case .duration:
+            let m = durationMinutes, s = durationSeconds
+            let hold = m > 0 && s > 0 ? "\(m)m \(s)s" : (m > 0 ? "\(m) min" : "\(s) sec")
+            return "\(sets) × \(hold)"
+        case .none:
+            return "\(sets) × \(reps) reps"
+        case .weight:
+            return "\(sets) × \(reps) × \(weightUnit.format(weight))"
+        }
+    }
+
     /// Minutes component of the total duration (for min:sec pickers).
     var durationMinutes: Int {
         get { durationTotalSeconds / 60 }

Shared/Model/Enums.swift

@@ -35,6 +35,24 @@ enum LoadType: Int, CaseIterable, Codable, Sendable {
     }
 }
 
+/// Which segment of a split an exercise belongs to — the split screen groups its
+/// exercise list by this. Persisted as its raw `Int` value; `main` is the default
+/// (and what older documents without the field decode to).
+enum ExerciseCategory: Int, CaseIterable, Codable, Sendable {
+    case main = 0
+    case warmup = 1
+
+    /// Order the categories appear on screen: warm-up first, then the main circuit.
+    static let displayOrder: [ExerciseCategory] = [.warmup, .main]
+
+    var displayName: String {
+        switch self {
+        case .main: "Main Circuit"
+        case .warmup: "Warm-up"
+        }
+    }
+}
+
 /// The kind of training a split represents — used to tag the Apple Health workout
 /// so it lands in the right category (and credits the rings correctly), and to pick
 /// a MET value when the phone has to estimate calories without watch sensor data.

Shared/Model/Mappers.swift

@@ -18,7 +18,8 @@ extension ExerciseDocument {
         self.init(id: e.id, name: e.name, order: e.order, sets: e.sets, reps: e.reps,
                   weight: e.weight, loadType: e.loadType, durationSeconds: e.durationTotalSeconds,
                   weightLastUpdated: e.weightLastUpdated,
-                  weightReminderWeeks: e.weightReminderTimeIntervalWeeks)
+                  weightReminderWeeks: e.weightReminderTimeIntervalWeeks,
+                  category: e.categoryRaw)
     }
 }
 
@@ -108,7 +109,8 @@ enum CacheMapper {
         Exercise(id: d.id, name: d.name, order: d.order, sets: d.sets, reps: d.reps, weight: d.weight,
                  loadType: d.loadType, durationTotalSeconds: d.durationSeconds,
                  weightLastUpdated: d.weightLastUpdated,
-                 weightReminderTimeIntervalWeeks: d.weightReminderWeeks)
+                 weightReminderTimeIntervalWeeks: d.weightReminderWeeks,
+                 categoryRaw: d.category ?? ExerciseCategory.main.rawValue)
     }
 
     private static func apply(_ d: ExerciseDocument, to e: Exercise) {
@@ -121,6 +123,7 @@ enum CacheMapper {
         e.durationTotalSeconds = d.durationSeconds
         e.weightLastUpdated = d.weightLastUpdated
         e.weightReminderTimeIntervalWeeks = d.weightReminderWeeks
+        e.categoryRaw = d.category ?? ExerciseCategory.main.rawValue
     }
 
     // MARK: Workout