fix: use iter_samples() instead of channels() for audio processing

Co-authored-by: aider (deepseek/deepseek-coder) <aider@aider.chat>

src/lib.rs

@@ -102,7 +102,7 @@ impl Plugin for ClipLauncher {
         }
 
         // Process audio
-        for channel in buffer.channels() {
+        for channel in buffer.iter_samples() {
             let input = channel.inputs;
             let output = channel.outputs;
             let num_samples = input.len();