Add CoreData-based workout tracking app with iOS and watchOS targets

- Migrate from SwiftData to CoreData with CloudKit sync
- Add core models: Split, Exercise, Workout, WorkoutLog
- Implement tab-based UI: Workout Logs, Splits, Settings
- Add SF Symbols picker for split icons
- Add exercise picker filtered by split with exclusion of added exercises
- Integrate IndieAbout for settings/about section
- Add Yams for YAML exercise definition parsing
- Include starter exercise libraries (bodyweight, Planet Fitness)
- Add Date extensions for formatting (formattedTime, isSameDay)
- Format workout date ranges to show time-only for same-day end dates
- Add build number update script
- Add app icons

Workouts Watch App/Utils/Date+Extensions.swift

@@ -0,0 +1,56 @@
+import Foundation
+
+extension Date {
+    func formattedDate() -> String {
+        let formatter = DateFormatter()
+        formatter.dateStyle = .short
+        formatter.timeStyle = .short
+        return formatter.string(from: self)
+    }
+
+    func formattedTime() -> String {
+        let formatter = DateFormatter()
+        formatter.dateStyle = .none
+        formatter.timeStyle = .short
+        return formatter.string(from: self)
+    }
+
+    func isSameDay(as other: Date) -> Bool {
+        Calendar.current.isDate(self, inSameDayAs: other)
+    }
+
+    func formatDate() -> String {
+        let formatter = DateFormatter()
+        formatter.dateStyle = .medium
+        formatter.timeStyle = .none
+        return formatter.string(from: self)
+    }
+
+    var abbreviatedMonth: String {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "MMM"
+        return formatter.string(from: self)
+    }
+
+    var dayOfMonth: Int {
+        Calendar.current.component(.day, from: self)
+    }
+
+    var abbreviatedWeekday: String {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "EEE"
+        return formatter.string(from: self)
+    }
+
+    func humanTimeInterval(to other: Date) -> String {
+        let interval = other.timeIntervalSince(self)
+        let hours = Int(interval) / 3600
+        let minutes = (Int(interval) % 3600) / 60
+
+        if hours > 0 {
+            return "\(hours)h \(minutes)m"
+        } else {
+            return "\(minutes)m"
+        }
+    }
+}