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

CLAUDE.md

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+# CLAUDE.md
+
+<!-- rgb(86, 20, 150); -->
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is a workout tracking iOS app built with Swift/SwiftUI, featuring both iPhone and Apple Watch companions. The app helps users manage workout splits, track exercise logs, and sync data across devices using CloudKit.
+
+## Development Commands
+
+### Building and Running
+- **Build the project**: Open `Workouts.xcodeproj` in Xcode and build (Cmd+B)
+- **Run on iOS Simulator**: Select the Workouts scheme and run (Cmd+R)
+- **Run on Apple Watch Simulator**: Select the "Workouts Watch App" scheme and run
+
+## Architecture
+
+### Data Layer
+- **CoreData**: Core persistence framework with CloudKit sync via `NSPersistentCloudKitContainer`
+- **CloudKit Container**: `iCloud.dev.rzen.indie.Workouts`
+- **PersistenceController**: Manages CoreData stack initialization, CloudKit configuration, and context access
+- **Models**: Located in `Models/` directory as NSManagedObject subclasses
+
+### Core Models
+- **Split**: Workout routine templates with exercises, colors, and system images
+- **Exercise**: Individual exercises within splits (sets, reps, weight, load type)
+- **Workout**: Active workout sessions linked to splits
+- **WorkoutLog**: Historical exercise completion records
+- **WorkoutStatus**: Enum for tracking workout/exercise completion states
+
+### Model Relationships
+```
+Split (1) ──cascade──> (many) Exercise
+Split (1) ──nullify──> (many) Workout
+Workout (1) ──cascade──> (many) WorkoutLog
+```
+
+### App Structure
+- **Dual targets**: Main iOS app (`Workouts/`) and Watch companion (`Workouts Watch App/`)
+- **Shared components**: Both apps have similar structure with platform-specific implementations
+- **TabView navigation**: Main app uses tabs (Workouts, Logs, Reports, Achievements)
+
+### CloudKit Integration
+- **Automatic sync**: Configured via `NSPersistentCloudKitContainerOptions`
+- **History tracking**: Enabled for CloudKit sync via `NSPersistentHistoryTrackingKey`
+- **Remote change notifications**: Enabled for real-time sync updates
+- **Cross-device sync**: Data syncs between iPhone and Apple Watch
+
+### UI Patterns
+- **SwiftUI-first**: Modern declarative UI throughout
+- **Environment injection**: ManagedObjectContext passed via `.environment(\.managedObjectContext)`
+- **Navigation**: Uses NavigationStack for hierarchical navigation
+- **Form-based editing**: Consistent form patterns for data entry
+
+### Key Directories
+- `Models/`: CoreData NSManagedObject subclasses
+- `Persistence/`: PersistenceController for CoreData stack management
+- `Views/`: UI components organized by feature (Splits, Exercises, Workouts, etc.)
+- `Utils/`: Shared utilities (date formatting, colors)
+- `*.xcdatamodeld`: CoreData model definition
+
+### CoreData Guidelines
+- Each model gets its own file in `Models/`
+- Use `@NSManaged` for all persistent properties
+- Implement `fetchRequest()` class methods for type-safe fetching
+- Use `NSSet` for to-many relationships with convenience array accessors
+- Implement add/remove helper methods for relationship management
+- Use appropriate delete rules: cascade for owned children, nullify for references
+
+### UI Guidelines
+- Tab-based root navigation with independent navigation stacks
+- Consistent form patterns for add/edit operations
+- Sheet presentations for modal operations
+- Swipe gestures for common actions (edit, complete, navigate)
+
+### Development Notes
+- **Preview support**: `PersistenceController.preview` for SwiftUI previews
+- **Color system**: Custom color extensions for consistent theming (`Color.color(from:)`)
+- **Date formatting**: Extensions in `Date+Extensions.swift`