Reconcile starter seeds on connect and add restore + duplicate cleanup

Seeding now covers existing installs, not just empty containers: after the
same settle delay as auto-seed, connect() branches to reconcileSeeds(),
driven by a pure tested planner — upgrade an older seed revision in place
(safe: clone-on-edit guarantees no user content at seed ULIDs), skip
up-to-date/quarantined files, respect delete-veto stubs, and write missing
seeds unless a same-name legacy split exists. Settings gains Restore
Starter Splits (the one deliberate veto lift, writing current bundle
bytes) and a dev duplicate-cleanup tool backed by a fail-closed scanner.
The HealthKit estimate now follows the clone redirect when resolving a
workout's split.

Claude-Session: https://claude.ai/code/session_01LEoff8bXGBS83tK1c55Mf7

Workouts/Seed/SplitSeeder.swift

@@ -1,32 +0,0 @@
-import Foundation
-import SwiftData
-
-/// The bundled immutable starter-split library, brought back on demand. The seeds
-/// themselves — fixed ULIDs, byte-canonical bundle JSON — live in `SeedLibrary`;
-/// editing one clones it and permanently tombstones the seed (see
-/// `SyncEngine.save(split:)`). The true first-run case is handled automatically by
-/// `SyncEngine.autoSeedIfEmpty`; this on-demand path (the "Add Starter Splits"
-/// button) is for a user who wants the starters back after removing some.
-enum SplitSeeder {
-    /// Add every starter split the user doesn't already have. For each seed:
-    ///   • skip if a live split with the same NAME exists — a user's edited clone of
-    ///     "Upper Body" must not be joined by a resurrected seed of the same name;
-    ///   • else if the seed was deleted (tombstoned), restore it (lifting the veto);
-    ///   • else write it fresh.
-    /// Seed `order` values are fixed (0–3); a collision with a user split's order is
-    /// an accepted cosmetic tie. Idempotent against double-taps and partial prior seeds.
-    @MainActor
-    static func seedDefaults(into context: ModelContext, using sync: SyncEngine) async {
-        let existing = (try? context.fetch(FetchDescriptor<Split>())) ?? []
-        let existingNames = Set(existing.map(\.name))
-
-        for seed in SeedLibrary.seeds {
-            if existingNames.contains(seed.doc.name) { continue }
-            if await sync.isTombstoned(id: seed.id) {
-                await sync.restoreSeed(seed)
-            } else {
-                await sync.writeSeed(seed)
-            }
-        }
-    }
-}