Workouts 2.0: re-base persistence on iCloud Drive documents

Replace Core Data + NSPersistentCloudKitContainer + App-Group store +
WatchConnectivity dictionary sync with the QuickRabbit iCloud-documents
architecture:

- iCloud Drive JSON documents are the sole source of truth (one file per
  aggregate: Splits/<ULID>.json, Workouts/YYYY/MM/<ULID>.json), with a
  rebuildable SwiftData cache populated only by an NSMetadataQuery observer
  and a connect-time reconcile. Soft-delete tombstones; hard iCloud gate.
- Shared model layer (ULID, Codable *Documents + stateless mappers, @Model
  cache entities, SwiftData container) compiled into both targets.
- New iPhone<->Watch bridge over WatchConnectivity keyed by ULIDs; the phone
  is the sole writer of iCloud Drive, the watch round-trips documents.
- AppServices DI + iCloud-required root gate; Swift 6 strict concurrency.
- Starter splits generated on demand from the bundled YAML catalogs.
- Migrate to XcodeGen (project.yml), iOS 26 / watchOS 26; CloudDocuments
  entitlement (drop CloudKit/App Group/aps-environment).
- Duration stored as Int seconds (was a Date epoch hack); fix workout
  end-on-create, undismissable delete dialog, toolbar-hiding nav stacks,
  and the Settings placeholder.
- Add README/CHANGELOG/LICENSE, .gitignore, refreshed REQUIREMENTS, and the
  Scripts/ TestFlight pipeline (release.sh + ASC API scripts).

MARKETING_VERSION 2.0.

README.md

@@ -0,0 +1,42 @@
+# Workouts
+
+A workout tracking app for iPhone and Apple Watch. Build workout splits, run
+sessions, and track your progress — with your data stored as plain JSON files in
+your own iCloud Drive.
+
+## Key Features
+
+- **Workout splits** — organize exercises into reusable routines with custom
+  colors and icons. Start with built-in starter splits (Upper Body / Core /
+  Lower Body) generated from a bundled exercise catalog.
+- **Exercise library** — a bundled catalog of starter exercises (bodyweight and
+  machine-based) to populate your splits.
+- **Run a workout** — start a session from a split, track sets/reps/weight or
+  timed exercises, and mark exercises complete.
+- **Progress tracking** — weight-progression charts per exercise across past
+  sessions.
+- **Apple Watch companion** — start and run workouts from the wrist; changes sync
+  back to the phone.
+- **iCloud Drive sync** — your data lives as human-readable JSON in your iCloud
+  Drive, synced across devices and visible in the Files app. iCloud is required.
+
+## Architecture
+
+iCloud Drive JSON documents are the **sole source of truth**; a local SwiftData
+store is a rebuildable read-through cache populated exclusively by an
+`NSMetadataQuery` observer (one-way flow: files → observer → cache). The phone is
+the only device that touches iCloud Drive; the Apple Watch is a thin remote that
+round-trips workout changes through the phone via WatchConnectivity.
+
+See `REQUIREMENTS.md` for the data model and `CLAUDE.md` for project guidance.
+
+## Building
+
+The Xcode project is generated with [XcodeGen](https://github.com/yonaskolb/XcodeGen):
+
+```sh
+xcodegen generate
+open Workouts.xcodeproj
+```
+
+Requires Xcode 26 (iOS 26 / watchOS 26, Swift 6).