Decouple transcripts from note text; end-to-end watch transfer acks

Schema v3: transcription attempts accumulate on AudioInfo (text, locale,
confidence, forced flag) — latest attempt is displayed, payload.text is
purely user writing, v2 notes migrate at read time. Editor shows the
transcript in its own live-updating section with insert-into-note; search
matches transcripts weighted by confidence. Watch recordings are now
deleted only on the phone's durable-ingest ack (transferUserInfo), closing
every phone-side loss window; failed sidecar writes unstage instead of
orphaning, and unreadable inbox recordings are surfaced in logs.

Claude-Session: https://claude.ai/code/session_014esDWi42URLEC6Cj17hGQ3

Notes/NotesApp.swift

@@ -33,8 +33,13 @@ struct NotesApp: App {
                     appServices = services
                     #if os(iOS)
                     // Hand the (already-activated) watch receiver the live sync
-                    // engine so a delivery arriving now drains immediately.
-                    appDelegate.watchReceiver.syncEngine = services.syncEngine
+                    // engine so a delivery arriving now drains immediately, and
+                    // route ingest acks back so the watch can free its copies.
+                    let receiver = appDelegate.watchReceiver
+                    receiver.syncEngine = services.syncEngine
+                    services.syncEngine.onWatchRecordingHandled = { [weak receiver] id in
+                        receiver?.acknowledgeIngest(id: id)
+                    }
                     #endif
                     await services.startDeferredServices()
                     if let pending = pendingBackupURL {