CLAUDE: Add velocity-count getters + DNN offset-channel overload

CuasRTUtils.getNumVout()/getSubDim() expose the 5D render dimensions for the
full-velocity-hyperstack memory estimate. CuasDnnInfer adds an inferROI(...,
double[][] offOut) overload that also returns the two offset channels
{dx, dy, s} per pixel (the DNN's per-pixel sub-pixel position estimate); the
existing 6-arg call delegates with offOut=null, so the field output is
unchanged. Both are prerequisites used by the CUAS-RT overhaul that follows.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/main/java/com/elphel/imagej/cuas/rt/CuasDnnInfer.java

@@ -69,6 +69,12 @@ public class CuasDnnInfer implements AutoCloseable {
      *  returns the C5P-shaped field [roi_npix][1][vdim*vdim] = softmax(vel)*s (confidence-gated
      *  velocity posterior per pixel) - plugs straight into showConvKernel5d / the recurrent layer. */
     public double[][][] inferROI(float[][] frames, int width, int height, Rectangle roi, int velRadius, double sThresh) throws Exception {
+        return inferROI(frames, width, height, roi, velRadius, sThresh, null);
+    }
+
+    /** As inferROI, but if offOut != null also fills offOut[roi_pix] = {dx, dy, s} from the two // By Claude on 06/14/2026
+     *  offset channels (op[1+nvel], op[1+nvel+1]) - the DNN's per-pixel sub-pixel position estimate. */
+    public double[][][] inferROI(float[][] frames, int width, int height, Rectangle roi, int velRadius, double sThresh, double[][] offOut) throws Exception {
         final int N = frames.length;
         final int P = 24, half = P / 2;                 // receptive field == training patch
         final int vdim = 2 * velRadius + 1, nvel = vdim * vdim;
@@ -100,6 +106,7 @@ public class CuasDnnInfer implements AutoCloseable {
                 for (int q = 0; q < bs; q++) {
                     float[][][] op = out[q];
                     float s = sigmoid(op[0][0][0]);
+                    if (offOut != null) offOut[base + q] = new double[] {op[1 + nvel][0][0], op[1 + nvel + 1][0][0], s}; // {dx,dy,s} for all pixels // By Claude on 06/14/2026
                     if (s < sThresh) continue;                       // below confidence -> leave field 0 // By Claude on 06/13/2026
                     double mx = Double.NEGATIVE_INFINITY;
                     for (int v = 0; v < nvel; v++) mx = Math.max(mx, op[1 + v][0][0]);

src/main/java/com/elphel/imagej/cuas/rt/CuasRTUtils.java

@@ -185,6 +185,10 @@ public class CuasRTUtils {
 		return kernel5d.length;
 	}
 
+	/** Number of output velocities (vout) and sub-pixel tiling of the 5D render - for memory estimates. // By Claude on 06/14/2026 */
+	public int getNumVout() { return kernel5d[0].length; }
+	public int getSubDim()  { return (int) Math.sqrt(kernel5d[0][0].length); }
+
 	/** Temporal taps (frames) of the direct pixel-domain fine-velocity kernel. */
 	public int getNumHistDirect() { // By Claude on 06/11/2026
 		return consolidationKernelDirect.getKernel().length;