Picking a preset no longer blinds the mode lamps

The six PRESET switches down the map's right flank stored their lamps in
modeLamp[], which holds four. Indices 4 and 5 ran off the end into
presetLamp[0..1], so the whole thing stayed self-consistent by memory
layout and nobody noticed - but it overwrote the four control-mode lamps
made moments earlier, and BASIC/STANDARD/VETERAN/MASTER on the upper-right
MFD were never lit again. presetLamp[], meanwhile, went unused.

The preset pass now fills the array it was always meant to, and the lamp
work moves out of the switch handler into a virtual NotifyOfPresetChange
that PresetEnable announces itself. That closes the second gap in passing:
keyboard 1-6 changed the mappings without touching the lamps, leaving the
flank showing a preset that was no longer in force. Both routes now go
through one place. The lamp arrays are also cleared in the constructor -
only the mapping loops ever filled them, and NOMODES skips those.

Verified by dumping the commanded RIO lamp states out of the running game
(PadRIO, TEST.EGG, at rest in Basic mode). Before and after are identical
except lamp 0x33, BASIC, which goes from 14 dim to 3c lit. The preset
lamps are unchanged: they worked by accident, and now work by
construction.

docs/CONTROL-PRESETS.md is the research behind it. The presets are not a
map feature at all - each is a complete factory layout for the four
mappable stick buttons, one mode-mask bit apiece, with all 26 vehicles
carrying their own six-preset table in RPL4.RES for both the pod RIO and
the Thrustmaster.

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

RP_L4/RPL4MPPR.h

@@ -104,6 +104,12 @@ ModeMask
 //
 void
 	PresetEnable(int preset_number);
+
+// Announced by PresetEnable for EVERY preset change, whichever way it was
+// triggered - map-flank switch or keyboard. Platforms carrying preset
+// lamps move them here; the base mapper has none.
+virtual void
+	NotifyOfPresetChange(int old_preset, int new_preset);
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // Protected data
 //
@@ -250,6 +256,9 @@ public:
 	void
 		NotifyOfConfigurationModeChange(Logical new_state);
 
+	void
+		NotifyOfPresetChange(int old_preset, int new_preset);
+
 	void
 		SetPerformance(Performance performance)
 			{