feat: AudioLevel helper and AudioRecorder.onLevel

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Sources/SstProbe/RecordProbe.swift

@@ -2,12 +2,13 @@ import AVFoundation
 import SstCore
 
 /// Records `seconds` of microphone audio; returns nil if access is denied or recording fails.
-func recordSamples(seconds: Double) async -> [Float]? {
+func recordSamples(seconds: Double, onLevel: ((Float) -> Void)? = nil) async -> [Float]? {
     guard await AVCaptureDevice.requestAccess(for: .audio) else {
         print("Microfoon-toegang geweigerd (Systeeminstellingen → Privacy → Microfoon).")
         return nil
     }
     let recorder = AudioRecorder()
+    recorder.onLevel = onLevel
     do { try recorder.start() } catch {
         print("start mislukt:", error.localizedDescription)
         return nil
@@ -18,7 +19,19 @@ func recordSamples(seconds: Double) async -> [Float]? {
 }
 
 func runRecordProbe() async {
-    guard let samples = await recordSamples(seconds: 3) else { return }
+    final class Levels: @unchecked Sendable {
+        let lock = NSLock()
+        var values: [Float] = []
+        func add(_ v: Float) { lock.withLock { values.append(v) } }
+    }
+    let levels = Levels()
+    guard let samples = await recordSamples(seconds: 3, onLevel: { levels.add($0) }) else { return }
     let peak = samples.map { abs($0) }.max() ?? 0
     print("samples: \(samples.count) (verwacht ≈ 48000), piek: \(peak)")
+    let values = levels.lock.withLock { levels.values }
+    if let lo = values.min(), let hi = values.max() {
+        print(String(format: "niveau-meldingen: %d (≈ %.0f per s), bereik %.1f … %.1f dBFS", values.count, Double(values.count) / 3, lo, hi))
+    } else {
+        print("geen niveau-meldingen ontvangen")
+    }
 }