Adjust rest time from the watch with the same 1-second stepper

A gear on the watch root opens a small Settings sheet whose stepper
edits the shared restSeconds default (10-180s, 1s steps). Edits ride a
new settingsUpdate message to the phone - debounced per stepper burst,
falling back to transferUserInfo when unreachable - which clamps the
value, writes the shared default, and re-echoes it to every device
through the application context. While an edit is pending on the watch,
an in-flight context's stale rest value is skipped so it can't yank the
stepper back mid-edit.

Workouts/Connectivity/PhoneConnectivityBridge.swift

@@ -249,6 +249,15 @@ final class PhoneConnectivityBridge: NSObject {
         liveRunState.apply(frame)
     }
 
+    /// A setting edited on the watch. The phone owns the durable value: clamp it, write
+    /// the shared default (the same store Settings' `@AppStorage` reads), and re-push the
+    /// application context so every device converges on it.
+    private func applySettingsUpdate(restSeconds: Int) {
+        let clamped = min(max(restSeconds, 10), 180)
+        UserDefaults.standard.set(clamped, forKey: WCPayload.restSecondsKey)
+        pushAll()
+    }
+
     /// Parse the (non-Sendable) WC dictionary in the nonisolated delegate context,
     /// then hop to the MainActor with only Sendable values.
     nonisolated private func route(_ dict: [String: Any]) {
@@ -259,6 +268,10 @@ final class PhoneConnectivityBridge: NSObject {
             if let doc = WCPayload.decodeWorkoutUpdate(dict) {
                 Task { @MainActor in await self.syncEngine.ingestFromWatch(doc) }
             }
+        case WCPayload.settingsUpdateType:
+            if let rest = WCPayload.decodeRestSeconds(dict) {
+                Task { @MainActor in self.applySettingsUpdate(restSeconds: rest) }
+            }
         case WCPayload.liveProgressType:
             if let frame = WCPayload.decodeLiveProgress(dict) {
                 Task { @MainActor in self.applyIncomingLive(frame) }