Ψ-W2-T2 remediation: atomic temp+rename collapse write, honest unknown-channel fallback, [verify — DAW] markers, corrected+filed bake-collapse deferral, observable collapse message, quiet-NaN test

src/core/model/bank_model.h

@@ -89,8 +89,10 @@ struct Sample {
     double wetDry = 1.0;            // 1.0 = fully wet, 0.0 = fully dry
 
     // Channels in the file this entry names — equal to its `fmt ` count by
-    // construction, which is what makes the instrument's mono/stereo read-out and
-    // its waveform lane count agree with the audio. 0 = unknown (pre-field entry).
+    // construction on every path that measures it, which is what makes the
+    // instrument's mono/stereo-toggle default agree with the audio (the waveform
+    // lane count reads the decoded file directly, not this field). 0 = unknown —
+    // a pre-field entry, or a capture whose file could not be parsed to measure it.
     int    channelCount = 0;
     int    sampleRate   = 0;