Un-pack the 7-display cockpit in-engine (L4MFDSPLIT=1)

The pod drove five monochrome MFDs from the color channels of two video
outputs - SVGA16 packs bit-slices of the shared gauge canvas into R/G/B
of gauge window 3 (upper MFDs) and R/G of window 4 (lower MFDs), with the
map palettized on the secondary and physically mounted portrait. The
desktop reconstruction previously required an external BitBlt-mirror
wrapper.

With L4MFDSPLIT=1, SVGA16 renders each display into its own window
(MFDSplitView, plain GDI) straight from the canvas + port bit-masks:
five green-screen MFD windows and the 90CW-rotated Map, tiled in the pod
grid to the right of the main view (L4MFDSCALE percent, default 50). The
packed D3D windows stay hidden but keep presenting off-screen, leaving
the original path untouched. Handles spanning mode (2-window setups).

Also: the plasma glass now opens directly below the main view (clamped
to the work area; L4PLASMAPOS=x,y overrides) per playtest feedback.

Verified: window grid comes up as main + 5 MFDs + Map + plasma with the
packed windows hidden; screenshots confirm a green MFD score readout and
the portrait tactical map rendering correctly. dist packer and BUILD.md
updated; the launcher wrapper is obsolete for split-mode use.

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

BUILD.md

@@ -112,7 +112,19 @@ Two new environment options remove the hardware dependency entirely:
   Hot-plugging works; with no controller it falls back to keyboard only.
 - **`L4PLASMA=SCREEN`** — renders the 128×32 plasma display as its own
   desktop window ("Plasma Display", plasma orange, `L4PLASMASCALE` sets the
-  pixel size, default 4). No COM port. Closing the window hides it.
+  pixel size, default 4). It opens directly below the main view;
+  `L4PLASMAPOS=x,y` overrides. No COM port. Closing the window hides it.
+- **`L4MFDSPLIT=1`** — un-packs the 7-display cockpit. The pod hardware
+  drove five monochrome MFDs from the color channels of two video outputs
+  (window 3 = upper MFDs in R/G/B, window 4 = lower MFDs in R/G) and
+  mounted the map display portrait. With split mode the game itself opens
+  seven proper windows — main view, five green-screen MFDs ("MFD upper
+  left/center/right", "MFD lower left/right") and the 90°-rotated "Map" —
+  rendered CPU-side from the shared gauge canvas; the packed windows stay
+  hidden. `L4MFDSCALE` sets the view size in percent of the gauge canvas
+  (default 50). Default layout is the pod grid to the right of the main
+  view; all windows are draggable. This replaces the external
+  BitBlt-mirror launcher wrapper.
 
 Bindings (vRIO's default profile, condensed):
 
@@ -136,6 +148,7 @@ DPLARG=1
 L4DPLCFG=RPDPL.INI
 L4GAUGE=640x480x16
 L4PLASMA=SCREEN
+L4MFDSPLIT=1
 TARGETFPS=60
 ```