Ship the border filler in the Windows installer, and count what is staged

The installer smoke test asserted seven model files, the number on the
day it was written; models/face has since gained the eye-state trio's
companions and the int8 detector forms, and the run on f71d7ba failed
with thirteen installed. The test now expects as many files as
package.sh's directories hold, so the next model needs no edit here.

package.sh also stages models/inpaint, which the APK and the Arch
package already carry and the Windows build did not: without
migan-512.onnx the panorama's border fill has no model on Windows.
xfeat needs nothing, it is embedded in the binary. windows.md §5.2
lists the result.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/windows.md

@@ -282,7 +282,9 @@ $LOCALAPPDATA\Programs\DarkRoom\
   models\
     scrfd_500m_640.onnx   scrfd_2.5g_640.onnx   scrfd_10g_640.onnx   arcface_mbf_b1.onnx
     2d106det_b1.onnx   ocec_s_b1.onnx   sgc_l_48_b1.onnx
+    scrfd_500m_640.int8.onnx   scrfd_2.5g_640.int8.onnx   scrfd_10g_640.int8.onnx
     yolo26s-sem-ade20k.onnx   yolo26s-sem-ade20k.classes.json   categories.txt
+    migan-512.onnx
   LICENSE
   uninstall.exe
 ```