jfjoch_process: --min-image-cc is in percent, not a fraction (fix crash)

--min-image-cc <num> is documented in percent and the per-image CC is a fraction in
[0,1], but the value was passed straight to MinCCForImage (which requires [0,1]), so
the documented usage (e.g. --min-image-cc 30) threw an uncaught JFJochException and
aborted. Divide the percent argument by 100.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tools/jfjoch_process.cpp

@@ -784,7 +784,7 @@ int main(int argc, char **argv) {
     // substantially. Off for non-rot3d (no combine). An explicit --capture-uncertainty always wins.
     scaling_settings.CaptureUncertaintyCoeff(capture_uncertainty_arg.value_or(combine_3d ? 1.0 : 0.0));
     scaling_settings.ForcedMosaicity(forced_mosaicity_arg);
-    scaling_settings.MinCCForImage(min_image_cc);
+    scaling_settings.MinCCForImage(min_image_cc / 100.0);   // --min-image-cc is in percent; the setting is a fraction
     if (outlier_reject_nsigma)
         scaling_settings.OutlierRejectNsigma(*outlier_reject_nsigma);
     scaling_settings.FileFormat(intensity_format);