fix: el tap del microfono seguia aislado al main actor (2.0.3 build 68)

El fix anterior arreglo los permisos —el crash se movio de start a beginSession,
y de TCC a AVAudioNodeTap::CheckEmitBuffer— pero el tap seguia petando.

Mi error: quitar el acceso a self del closure no elimina la inferencia de
aislamiento. La inferencia viene de DONDE se escribe el closure, no de lo que
captura. Escrito dentro de un metodo @MainActor, seguia siendo main-actor
isolated, y el tap se dispara desde el hilo de audio en tiempo real.

Ahora el handler se construye en makeTapHandler, que es nonisolated, y se pasa a
installTap. La estructura se auto-verifica: quitarle nonisolated a makeTapHandler
no compila, porque installTap es nonisolated y no puede llamar a un metodo
aislado. El bug pasa de crash en produccion a error de compilacion.

Tests: testTapHandlerRunsOffTheMainThread invoca el handler desde una cola de
fondo, que es exactamente la condicion que trapeaba. No hace falta microfono; el
intento anterior con AVAudioEngine se saltaba siempre porque el simulador no
tiene entrada de audio utilizable.

Barrido del mismo patron en el resto de servicios @MainActor: CalendarService y
NotificationService usan las variantes async/await, que estan anotadas y no
tienen closures. SpeechDictationService era el unico sitio.

Lanes feedback y crashlog para leer los reportes de TestFlight desde la API:
spaceship apunta a v1/betaFeedbacks, que Apple ya retiro; el endpoint vivo es
v1/apps/<id>/betaFeedbackCrashSubmissions y el log viene inline en logText.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Ks8uUcMA9mjypVK7F2Pkt

MealMood/Services/SpeechDictationService.swift

@@ -73,6 +73,35 @@ final class SpeechDictationService: ObservableObject {
         }
     }
 
+    /// Installs the microphone tap from a `nonisolated` context.
+    ///
+    /// `AVAudioNodeTapBlock` is pre-concurrency, so a closure literal written
+    /// inside a `@MainActor` method is inferred main-actor isolated — and the tap
+    /// is fired from the realtime audio thread, so Swift 6's isolation check
+    /// trapped there. Dropping the `self` access was not enough: the inference
+    /// comes from where the closure is *written*, not from what it captures.
+    /// Declaring these helpers `nonisolated` is what actually removes it.
+    ///
+    /// The handler is built here, in a `nonisolated` context, and handed to
+    /// `installTap` rather than written inline at the call site — that is the
+    /// whole point, and it is also what makes it testable: a test can call this
+    /// and invoke the result off the main thread, which is exactly the condition
+    /// that trapped, without needing a working microphone.
+    nonisolated static func makeTapHandler(
+        feeding request: SFSpeechAudioBufferRecognitionRequest
+    ) -> (AVAudioPCMBuffer, AVAudioTime) -> Void {
+        { buffer, _ in
+            request.append(buffer)
+        }
+    }
+
+    nonisolated static func installTap(on node: AVAudioInputNode,
+                                       format: AVAudioFormat,
+                                       feeding request: SFSpeechAudioBufferRecognitionRequest) {
+        node.installTap(onBus: 0, bufferSize: 1024, format: format,
+                        block: makeTapHandler(feeding: request))
+    }
+
     private func beginSession(localeIdentifier: String) {
         guard let recognizer = SFSpeechRecognizer(locale: Locale(identifier: localeIdentifier)),
               recognizer.isAvailable else {
@@ -96,12 +125,7 @@ final class SpeechDictationService: ObservableObject {
             let inputNode = audioEngine.inputNode
             let format = inputNode.outputFormat(forBus: 0)
             inputNode.removeTap(onBus: 0)
-            // Captures the request directly instead of reaching through `self`:
-            // this runs on the realtime audio thread, which must never touch
-            // main-actor state. `append` is designed to be fed from that thread.
-            inputNode.installTap(onBus: 0, bufferSize: 1024, format: format) { buffer, _ in
-                request.append(buffer)
-            }
+            Self.installTap(on: inputNode, format: format, feeding: request)
 
             audioEngine.prepare()
             try audioEngine.start()