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

README.md

@@ -64,9 +64,13 @@ your own iCloud Drive.
   planned reps and weight, and the rest and finish pages offer a small adjust
   pill to correct what you actually did (in 2.5 lb / 1.25 kg steps) without
   breaking the flow; the completed-exercise page shows the recorded sets.
-- **Progress tracking** — weight-progression charts per exercise across past
-  sessions, plotting the top-set weight you actually lifted; workout volume
-  sums the recorded sets too.
+- **Progress tab** — per-goal adherence tracks (a 12-week strip per goal with
+  weekly streaks and per-schedule this-week dots), this-week totals with
+  vs-last-week deltas, trend charts (workouts, volume, active time, energy over
+  7D–All ranges), weight-progression charts per exercise plotting the top-set
+  weight you actually lifted, a derived achievements gallery, and full workout
+  history — everything recomputed from your workout files, nothing separately
+  stored.
 - **Apple Watch companion** — starting a workout on the iPhone launches the watch
   app straight into it. The watch lists your in-progress workouts; pick one, pick an
   exercise, and run it as a paged flow: a **Ready?** lead-in, count-up work phases,