Initial commit: bt411 -- standalone Windows BattleTech (Tesla 4.10 port)

Clean, self-contained extraction of the BattleTech-specific work from the
reverse-engineering workspace -- engine + game + content + build, with nothing
from Red Planet or the raw archive dumps. Builds green (Win32) and runs the
single-player drive->animate->target->fire->damage->destroy loop out of the box.

Layout:
  engine/   MUNGA + MUNGA_L4 shared 2007 engine, carrying our BT render/loader
            work (bgfload/L4D3D/L4VIDEO: BSL bit-slice decode, LOD/ground/shadow
            models) + image codec; the minimal rp/ headers the audio HAL needs
  game/     reconstructed BT logic + surviving-original BT source + fwd shims
            + WinMain launcher
  content/  full runtime tree (BTL4.RES, VIDEO/, GAUGE/, AUDIO/, eggs, BTDPL.INI)
  docs/     format specs + reconstruction ledgers
  reference/ raw Ghidra pseudocode (recon source-of-truth) + decomp exporter
  tools/    MP console emulator + map/resource scanners

One top-level CMake builds munga_engine lib + bt410_l4 game lib + btl4.exe.
All paths relativized (186 fwd shims + ~437 CMake abs paths -> repo-relative);
DXSDK is the one external, overridable via -DDXSDK. Verified: builds to a
byte-identical 2.27MB exe and runs combat (TARGET DESTROYED, 0 crashes) against
the bundled content.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

engine/MUNGA/CAMMPPR.h

@@ -0,0 +1,110 @@
+#pragma once
+
+#include "subsystm.h"
+#include "camship.h"
+#include "controls.h"
+
+//##########################################################################
+//#######################    CameraControlsMapper   ########################
+//##########################################################################
+class CameraControlsMapper : public Subsystem
+{
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// Shared Data support
+//
+public:
+	static Derivation *GetClassDerivations();
+	static SharedData DefaultData;
+
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// Messaging Support
+//
+public:
+	enum
+	{
+		KeypressMessageID = Subsystem::NextMessageID,
+		DirectorModeMessageID,
+		IncrementCameraMessageID,
+		DecrementCameraMessageID,
+		CreateCameraInstanceMessageID,
+		DeleteCameraInstanceMessageID,
+		OutputCameraInstancesMessageID,
+		NextMessageID
+	};
+
+	void KeypressMessageHandler(ReceiverDataMessageOf<ControlsKey> *message);
+
+	void DirectorModeMessageHandler(ReceiverDataMessageOf<ControlsButton> *message);
+
+	void IncrementCameraMessageHandler(ReceiverDataMessageOf<ControlsButton> *message);
+
+	void DecrementCameraMessageHandler(ReceiverDataMessageOf<ControlsButton> *message);
+
+	void CreateCameraInstanceMessageHandler(ReceiverDataMessageOf<ControlsButton> *message);
+
+	void DeleteCameraInstanceMessageHandler(ReceiverDataMessageOf<ControlsButton> *message);
+
+	void OutputCameraInstancesMessageHandler(ReceiverDataMessageOf<ControlsButton> *message);
+
+protected:
+	static const HandlerEntry MessageHandlerEntries[];
+	//static MessageHandlerSet MessageHandlers;
+	static MessageHandlerSet& GetMessageHandlers();
+
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// Attribute Support
+//
+public:
+	enum
+	{
+		StickPositionAttributeID = Subsystem::NextAttributeID,
+		ThrottlePositionAttributeID,
+		PedalsPositionAttributeID,
+		ReverseThrustAttributeID,
+		DriveCameraAttributeID,
+		SlideOrClampAttributeID,
+		NextAttributeID
+	};
+private:
+	static const IndexEntry AttributePointers[];
+
+protected:
+	//static AttributeIndexSet AttributeIndex
+	static AttributeIndexSet& GetAttributeIndex();
+
+//
+// public attribute declarations go here
+//
+public:
+	ControlsJoystick	stickPosition;
+	Scalar				throttlePosition;
+	Scalar				pedalsPosition;
+	ControlsButton  	reverseThrust;
+	ControlsButton		driveCamera;
+	ControlsButton		slideOrClamp;
+
+//##########################################################################
+// Model support
+//
+public:
+	CameraShip* GetEntity()		{ return (CameraShip*)Subsystem::GetEntity(); }
+
+	typedef void (CameraControlsMapper::*Performance)(Scalar time_slice);
+
+	void SetPerformance(Performance performance)
+	{
+		Check(this);
+		activePerformance = (Simulation::Performance)performance;
+	}
+
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// Construction and Destruction
+//
+protected:
+	CameraControlsMapper(CameraShip *owner, int subsystem_ID, SubsystemResource *subsystem_resource, SharedData &shared_data);
+
+public:
+	~CameraControlsMapper();
+
+	Logical TestInstance() const;
+};