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

Workouts/Views/Common/WorkoutStarter.swift

@@ -0,0 +1,45 @@
+//
+// WorkoutStarter.swift
+// Workouts
+//
+// Copyright 2026 Rouslan Zenetl. All Rights Reserved.
+//
+
+import IndieSync
+import Foundation
+
+/// The one place a workout is created from a routine. Both start paths — the routine
+/// picker sheet and the Today board — call this so the plan-time log snapshot and
+/// the returned id stay identical per site.
+@MainActor
+enum WorkoutStarter {
+    /// Builds and saves a fresh workout from a routine (plan-time log snapshot per
+    /// exercise) and returns the new workout's id so the caller can navigate once the
+    /// cache catches up. Deliberately does NOT touch the watch: the wrist session
+    /// launches only when the first exercise actually starts (see
+    /// `SyncEngine.onWorkoutBecameActive`), so a peek-then-back never spins one up.
+    static func start(routine: Routine, sync: SyncEngine) async -> String {
+        let startDate = Date()
+        let logs = routine.exercisesArray.enumerated().map { index, exercise in
+            WorkoutLogDocument(planFrom: ExerciseDocument(from: exercise), order: index, date: startDate)
+        }
+
+        // A freshly started workout has no `end` — only completion stamps it.
+        let doc = WorkoutDocument(
+            schemaVersion: WorkoutDocument.currentSchemaVersion,
+            id: ULID.make(),
+            routineID: routine.id,
+            routineName: routine.name,
+            start: startDate,
+            end: nil,
+            status: WorkoutStatus.notStarted.rawValue,
+            createdAt: startDate,
+            updatedAt: startDate,
+            logs: logs,
+            restSeconds: routine.restSeconds, autoAdvance: routine.autoAdvance
+        )
+
+        await sync.save(workout: doc)
+        return doc.id
+    }
+}