Add AAC support and update version

This commit adds support for AAC audio decoding via the fdk-aac library, including:
- New AAC decoder module (ADTS streaming)
- Integration into the autodetection system
- Support for AAC in transcoding
- Updated version to 0.3.23
- Added necessary dependencies in Cargo.toml and Cargo.lock
- Added tests for AAC decoding

pmoflac/tests/aac_decode.rs

@@ -0,0 +1,43 @@
+use pmoflac::decode_aac_stream;
+use tokio::io::AsyncReadExt;
+
+#[tokio::test]
+async fn test_decode_adts_file() {
+    let file = tokio::fs::File::open("/tmp/test_adts.aac")
+        .await
+        .expect("test ADTS file not found — run: ffmpeg -i tests/SBRtestStereoHiBr.mp4 -vn -acodec copy -f adts /tmp/test_adts.aac");
+
+    let mut stream = decode_aac_stream(file)
+        .await
+        .expect("decode_aac_stream failed");
+
+    let info = stream.info().clone();
+    println!("StreamInfo: {} Hz, {} ch, {} bps", info.sample_rate, info.channels, info.bits_per_sample);
+
+    assert!(info.sample_rate > 0, "sample_rate should be > 0");
+    assert!(info.channels == 1 || info.channels == 2, "channels should be 1 or 2");
+    assert_eq!(info.bits_per_sample, 16);
+
+    let mut pcm = Vec::new();
+    stream.read_to_end(&mut pcm).await.expect("read_to_end failed");
+
+    println!("Decoded {} PCM bytes ({} samples)", pcm.len(), pcm.len() / 2);
+    assert!(pcm.len() > 0, "should have decoded some PCM data");
+}
+
+#[tokio::test]
+async fn test_autodetect_adts() {
+    use pmoflac::decode_audio_stream;
+
+    let file = tokio::fs::File::open("/tmp/test_adts.aac")
+        .await
+        .expect("test ADTS file not found");
+
+    let stream = decode_audio_stream(file)
+        .await
+        .expect("decode_audio_stream failed");
+
+    let info = stream.info().clone();
+    println!("Autodetect: {} Hz, {} ch, {} bps", info.sample_rate, info.channels, info.bits_per_sample);
+    assert!(info.sample_rate > 0);
+}