MFD rendering: HALFTONE downscale, plus the exploded diagnostic view

Two pieces of MFD work that had been sitting in the tree (already in
every build and dist since).

The compact cockpit glass shows the full 640x480 gauge canvas at about
half size, and COLORONCOLOR did that by dropping every other row and
column - which shredded the 1-bit vector strokes and small text.
HALFTONE area-averages instead (with the brush origin set, as MSDN
requires) so the downscaled MFDs stay legible.

L4MFDSPLIT=2 adds an exploded diagnostic view: every display in its
own full-size desktop window at native resolution, decoded exactly as
the pod VDB split them from the single gauge canvas, with no cockpit
compositing and no downscale. It makes an individual MFD readable and
screenshottable at full resolution for comparison against the
emulator per-channel reference windows. L4MFDSPLIT=1 keeps the
composited glass cockpit and stays the default.

Also: .gitignore now covers the packaged RedPlanet-*.zip releases,
which live on the Gitea release page rather than in the tree.

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

MUNGA_L4/L4MFDVIEW.cpp

@@ -342,7 +342,12 @@ void
 
 	FillRect(mem, &client, (HBRUSH) GetStockObject(BLACK_BRUSH));
 
-	SetStretchBltMode(mem, COLORONCOLOR);
+	// HALFTONE area-averages the downscale (the compact glass shows the
+	// full 640x480 canvas at ~half size); COLORONCOLOR dropped every other
+	// row/column, which shredded the 1-bit vector strokes and small text.
+	// HALFTONE requires the brush origin be set (MSDN).
+	SetStretchBltMode(mem, HALFTONE);
+	SetBrushOrgEx(mem, 0, 0, NULL);
 	StretchDIBits(
 		mem,
 		displayX, displayY, displayW, displayH,