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>

content/CONTROLS.MAP

@@ -32,7 +32,7 @@
 # <src>     LeftStickX LeftStickY RightStickX RightStickY
 #           LeftTrigger RightTrigger
 # action    ViewToggle LookBehind AllStop ModeCycle DisplayCycle Valve Flush
-#           ConfigHold Generator1-4 Reconnect
+#           ConfigHold Generator1-4 Reconnect Mfd1Cycle Mfd2Cycle Mfd3Cycle
 # pckey     sends an authentic 1995 PC-keyboard hotkey (the in-cockpit
 #           dispatcher): '+'/'-' = target zoom, 'w'..'o' = pilot select,
 #           'a','b','c','d','f','g','s','v','x','z' = display presets, ...
@@ -76,6 +76,9 @@ key C     action Valve         # coolant valve cycle
 key H     action Flush         # coolant flush (HOLD -- dumps reservoir coolant)
 key M     action ModeCycle     # Basic -> Standard -> Veteran controls
 key N     action DisplayCycle  # secondary schematic: Damage -> Critical -> Heat
+key J     action Mfd1Cycle     # lower-left MFD page: Quad -> Eng detail pages
+key K     action Mfd2Cycle     # upper-center MFD page (engineering)
+key L     action Mfd3Cycle     # lower-right MFD page
 key V     action ViewToggle    # cockpit <-> chase camera (dev)
 key B     action LookBehind    # HOLD = the pod's rear-view button
 key F5    action Generator1

content/CONTROLS_NUMPAD.MAP

@@ -53,6 +53,9 @@ key F7      action Generator3
 key F8      action Generator4
 key F9      action Reconnect
 key F10     action Valve
+key J       action Mfd1Cycle   # lower-left MFD page: Quad -> Eng detail pages
+key K       action Mfd2Cycle   # upper-center MFD page (engineering)
+key L       action Mfd3Cycle   # lower-right MFD page
 
 # ---- Upper MFD banks: number row = the top aux row, QWERTY row = the row
 # ---- under it, left to right across the Left / Center / Right panels.