Gitea #9: the upper-MFD PRESET pages (3 MFDs x 5) live -- SetPresetMode

table re-decoded to the ModeMFD bits + desktop J/K/L page cycle

The preset system was unwired by ONE defect in the message layer: the
SetPresetMode @004d1b24 table @0051dbf0 had been transcribed from the
section dump as BIG-endian dwords ({0x1e,0x01000000} instead of
{0x1e,0x01}), so a preset press set a garbage high bit -- and for group 1
items 3-4 / group 2 items 0-2 stomped the LIVE NonMapping / Intercom /
ModeSecondary* bits -- while the real page bits never moved.  Ground
truth (section_dump.txt:72901-72908, little-endian + BTL4MODE.HPP [T0]):
set = ModeMFD{1,2,3}{Quad,Eng1-4} = 1<<(group*5+item), bits 0-14, fully
disjoint from the #6 secondary trio (bits 18-20); group 2 is MFD3, NOT a
duplicate of the secondary views.

What the 15 presets show (l4gauge.cfg): group = the MFD (Mfd1 lower left
/ Mfd2 upper center / Mfd3 lower right), item 0 = the btquad.pcx Quad
overview (up to 4 vehicleSubSystems cluster panels), items 1-4 = the
full-screen engineering-detail pages (bteng.pcx + prepEngr screens
group*4+1..4 + the cluster eng children: GENERATOR SELECT A-D, POWER
graph, COOLING loop, DAMAGE, ammo).  Empty screens are authored per mech
(Blackhawk: 3/11/12 empty).

Authentic dispatch (streamed "L4" .CTL EventMappings, BT_CTRLMAP_LOG
dump): each MFD owns the 8-button RIO bank around it, MODE-MASK-gated --
Mfd1 = 0x08-0x0F, Mfd2 = 0x20-0x27, Mfd3 = 0x00-0x07.  Quad page ->
direct-select buttons for the POPULATED eng pages (mapper msgs
Aux1Eng1-4 0x4-0x7 / Aux2* 0x9-0xC / Aux3* 0xE-0x11); eng page -> one
back-to-Quad button (0x3/0x8/0xD) + per-subsystem controls.  These
records already install and fire on desktop (btinput passes the live
manager mask), so the NUMPAD profile's 0x20-0x27 keys page MFD2
authentically.

Port wiring (the #6 pattern): keys J/K/L -> actions Mfd1/2/3Cycle ->
gBTPresetCycle -> L4MechControlsMapper::CyclePresetModeNow(group) -- a
documented desktop shim (24 mode-dependent pod buttons don't fit a
keyboard) that cycles Quad -> populated Eng pages -> Quad, visiting
exactly the pod-reachable set; the body is the authentic SetPresetMode.

Dev-composite: BTDrawGaugeSurfaces now draws the Eng1-3 planes at their
sibling cells and skips any mono plane whose channel is BlankColor,
honoring the mode-driven reconfigure (RemapGraphicsPort) -- each dev
cell shows the ACTIVE page like the pod monitor.  This supersedes and
removes the 2026-07-12 GAUGREND "frozen-dial" scaffold (forced all 15
page bits active under BT_DEV_GAUGES; it pinned the shared Eng plane on
the highest screen and ate the page flips).

Pixel-verified (BT_PRESET_TEST + BT_DEV_GAUGES_DOCK + BT_SHOT,
Blackhawk): all three MFDs page Quad -> SYSTEM NN eng details -> back to
Quad in lockstep with the [mode] preset mask log; group 0 skips the
authored-empty screen 3, group 2 skips 11/12.  Un-regressed: N display
cycle (0x450421->0x490421->0x510421, page bits intact), M control mode,
CONTROLS.MAP 52 bindings parse clean.

Diags: BT_MODE_LOG ([mode] preset), BT_PRESET_TEST=<frame>.

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

game/reconstructed/btinput.cpp

@@ -79,6 +79,9 @@ enum BTActionID
 	BTActGenerator3,
 	BTActGenerator4,
 	BTActReconnect,
+	BTActMfd1Cycle,			// Gitea #9: cycle the lower-left MFD preset page
+	BTActMfd2Cycle,			// Gitea #9: cycle the upper-center MFD preset page
+	BTActMfd3Cycle,			// Gitea #9: cycle the lower-right MFD preset page
 	BTActCount
 };
 
@@ -199,6 +202,8 @@ static const BTName sActionNames[] =
 	{"Generator1", BTActGenerator1}, {"Generator2", BTActGenerator2},
 	{"Generator3", BTActGenerator3}, {"Generator4", BTActGenerator4},
 	{"Reconnect", BTActReconnect},
+	{"Mfd1Cycle", BTActMfd1Cycle}, {"Mfd2Cycle", BTActMfd2Cycle},
+	{"Mfd3Cycle", BTActMfd3Cycle},
 	{0, 0}
 };
 
@@ -269,6 +274,9 @@ static const char *sDefaultProfile =
 	"key H     action Flush\n"
 	"key M     action ModeCycle\n"
 	"key N     action DisplayCycle\n"
+	"key J     action Mfd1Cycle\n"
+	"key K     action Mfd2Cycle\n"
+	"key L     action Mfd3Cycle\n"
 	"key V     action ViewToggle\n"
 	"key B     action LookBehind\n"
 	"key F5    action Generator1\n"
@@ -971,6 +979,9 @@ void
 				case BTActValve:		next.valve = 1; break;
 				case BTActFlush:		next.flush = 1; break;
 				case BTActConfigHold:	next.configHold = 1; break;
+				case BTActMfd1Cycle:	next.mfdCycle[0] = 1; break;
+				case BTActMfd2Cycle:	next.mfdCycle[1] = 1; break;
+				case BTActMfd3Cycle:	next.mfdCycle[2] = 1; break;
 				case BTActGenerator1:	next.genSel = 4; break;
 				case BTActGenerator2:	next.genSel = 5; break;
 				case BTActGenerator3:	next.genSel = 6; break;