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

WorkoutsTests/SeedLibraryTests.swift

@@ -4,30 +4,30 @@ import Testing
 import IndieSync
 @testable import Workouts
 
-/// Locks the bundled starter-split library end to end: the catalog decodes and
+/// Locks the bundled starter-routine library end to end: the catalog decodes and
 /// orders correctly, the pinned seed ids never drift, a pristine save re-emits
 /// byte-identical JSON (no phantom iCloud churn), every seed passes the
 /// forward-compatibility gate, and `isPristine` tracks edits correctly through
 /// both the raw document and a SwiftData cache round-trip.
 struct SeedLibraryTests {
 
-    @Test func catalogLoadsThirteenSeedsInOrder() {
+    @Test func catalogLoadsFourteenSeedsInOrder() {
         let seeds = SeedLibrary.seeds
-        #expect(seeds.count == 13)
-        #expect(seeds.map(\.doc.order) == Array(0...12))
+        #expect(seeds.count == 14)
+        #expect(seeds.map(\.doc.order) == Array(0...13))
         #expect(seeds.map(\.doc.name) == [
             "Upper Body", "Core", "Lower Body", "Bodyweight Core",
             "Full Body Machines", "Free Weight Basics",
             "Upper Body Warm-Up", "Lower Body Warm-Up",
             "Morning Wake-Up", "Morning Mobility",
-            "Full Body Stretch", "Evening Stretch", "Cardio",
+            "Full Body Stretch", "Evening Stretch", "Cardio", "Meditation",
         ])
     }
 
     /// These ids are minted from a frozen 2020 timestamp and are already shipped
     /// inside installed app bundles. Changing any of them breaks cross-device
     /// convergence (two devices would mint different ids for "the same" starter
-    /// split) and voids the permanent-tombstone exemption that lets an
+    /// routine) and voids the permanent-tombstone exemption that lets an
     /// edited-then-deleted seed's stub veto resurrection forever — regenerate
     /// only with extreme care, and never for a seed that has already shipped.
     @Test func seedIDsArePinned() {
@@ -45,6 +45,7 @@ struct SeedLibraryTests {
             "01DXF6DT003PRJB3FGYSSGTQ5X", // Full Body Stretch
             "01DXF6DT00M5YRFPHJQ2FS2B9P", // Evening Stretch
             "01DXF6DT00BXJ6N63ZBX9M9VNH", // Cardio
+            "01DXF6DT00ANFJR7GX9G808G4M", // Meditation
         ])
     }
 
@@ -59,7 +60,7 @@ struct SeedLibraryTests {
     @Test func allSeedsAreReadableAtCurrentSchemaVersion() {
         for seed in SeedLibrary.seeds {
             #expect(seed.doc.isReadable)
-            #expect(seed.doc.schemaVersion == SplitDocument.currentSchemaVersion)
+            #expect(seed.doc.schemaVersion == RoutineDocument.currentSchemaVersion)
         }
     }
 
@@ -102,13 +103,13 @@ struct SeedLibraryTests {
     }
 
     /// Round-trips every seed through the SwiftData cache the way the metadata
-    /// observer would (document → `CacheMapper.upsertSplit` → entity), then
+    /// observer would (document → `CacheMapper.upsertRoutine` → entity), then
     /// rebuilds a document from that entity the way the write path would. The
     /// result must still read as pristine, or every user's very first cache
-    /// rebuild would silently fork their starter splits.
+    /// rebuild would silently fork their starter routines.
     @MainActor
     @Test func mapperRoundTripPreservesPristineness() throws {
-        let schema = Schema([Split.self, Exercise.self, Workout.self, WorkoutLog.self])
+        let schema = Schema([Routine.self, Exercise.self, Workout.self, WorkoutLog.self])
         // cloudKitDatabase: .none matches WorkoutsModelContainer — without it SwiftData
         // applies CloudKit schema validation (all relationships optional), which the
         // cache entities intentionally don't satisfy.
@@ -117,9 +118,9 @@ struct SeedLibraryTests {
         let context = ModelContext(container)
 
         for seed in SeedLibrary.seeds {
-            CacheMapper.upsertSplit(seed.doc, relativePath: seed.doc.relativePath, into: context)
-            let entity = try #require(CacheMapper.fetchSplit(id: seed.id, in: context))
-            let rebuilt = SplitDocument(from: entity)
+            CacheMapper.upsertRoutine(seed.doc, relativePath: seed.doc.relativePath, into: context)
+            let entity = try #require(CacheMapper.fetchRoutine(id: seed.id, in: context))
+            let rebuilt = RoutineDocument(from: entity)
             #expect(SeedLibrary.isPristine(rebuilt))
         }
     }