data: record the dt-side S50C training state

Seven new .mp fits from the fine/test sweeps (0.0001 .. 0.3), the S50C
workpiece material and CuttingParameter side-files they reference, the
schema-migrated S50C.hincproj, and the test-err-ratio project. These were
produced by runs on HiNC-1 and existed only in dt's working tree.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

BT40-ER16-090.Holder

@@ -2,7 +2,7 @@
 <CylindroidHolder>
   <Name>default</Name>
   <Note>BT40-ER16-090</Note>
-  <Cylindroid LongitudeNum="24">
+  <Cylindroid>
     <PairZr>(0,25)</PairZr>
     <PairZr>(36.5,25)</PairZr>
     <PairZr>(36.5,44.5)</PairZr>
@@ -10,4 +10,10 @@
     <PairZr>(106.6,40)</PairZr>
     <PairZr>(136.44,40)</PairZr>
   </Cylindroid>
+  <PolarResolution2d>
+    <PolarResolution2d>
+      <LinearResolution_mm>0.5</LinearResolution_mm>
+      <AngleResolution_deg>5</AngleResolution_deg>
+    </PolarResolution2d>
+  </PolarResolution2d>
 </CylindroidHolder>