Fix two Jul-16 regressions: BT_DEV_GAUGES crash + -net dead controls mapper

Both surfaced today (dormant ~1 day) the moment the pod launch flags
(BT_DEV_GAUGES=1 BT_START_INSIDE=1, tools/mp_launch.sh) were used to drive in
multiplayer -- which made the same-day paint change look guilty.  Confirmed on
the pre-paint build too; the trigger was the Jul-16 audio attribute work.

1) BT_DEV_GAUGES crash (cdb: CoolingLoopConnection::Update, ~15s in as the gauge
   builds lazily).  The dev-gauge cooling-loop lamp reached the cooling master by
   RAW attribute index -- GetAttributePointer(3) + *(master+0x1d4).  The audio
   commits (cc2b109 ReportLeak etc.) inserted rows into the chained attribute
   tables, so index 3 shifted onto a scalar, the resolve walked garbage, and the
   background pass AV'd.  Fix: route through a complete-type bridge reading NAMED
   members (heat.cpp BTCoolingLoopFrame: linkedSinks.Resolve() +
   Condenser::condenserNumber) -- the databinding rule; never a raw numeric
   attribute index.  Removed the now-orphaned GetAttributePointer-by-index
   helper.  Name-keyed samplers (InputVoltage) were unaffected.

2) -net dead controls mapper (mech wouldn't walk; turning/weapons still worked).
   The RIO mapper is built from a stack SubsystemResource in btl4app.cpp that set
   only name/classID/modelSize -- leaving subsystemFlags as stack GARBAGE, which
   Subsystem::Subsystem copies into simulationFlags.  A stray DontExecuteFlag
   (0x2) froze the mapper (speedDemand stuck at 0).  Config-dependent: clean in
   SP, dirty in -net; the audio commits shifted the stack and flipped the bit.
   Fix: memset each hand-built control-mapper resource to 0 (flags 0 =
   AlwaysExecute, the faithful value -- a mapper must tick every frame).

Verified with the pod launch flags: SP alive 32s no crash; MP mech walks
(speedDemand 61.5 at full throttle, ~430u traveled), both nodes alive, no crash.

KB: reconstruction-gotchas.md gains gotcha 18 (uninitialized stack-resource
flags + the raw-attribute-index-into-a-growing-table variant) and a
verify-under-the-user's-launch-flags note.

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

game/reconstructed/heat.cpp

@@ -1123,3 +1123,31 @@ Subsystem *CreateCondenserSubsystem(Mech *owner, int id, void *seg)
 
 // CreateHeatSinkBankSubsystem (0xBBE) now lives in heatfamily_reslice.cpp -- it
 // builds the real AggregateHeatSink (which needs that TU's class definition).
+
+//===========================================================================//
+// Gauge cooling-loop bridge (task #7 regression fix, 2026-07-17).
+//
+// The dev-gauge CoolingLoopConnection (btl4gau2.cpp @004c31a0) reached the
+// cooling master with a RAW attribute index (GetAttributePointer(3)) and then
+// raw-read master+0x1d4.  The binary heat attribute table (@0x50e438..0x50e4c8)
+// shows id 3 == "HeatSink" == the linkedSinks plug, and +0x1d4 on the resolved
+// master is Condenser::condenserNumber (the loop number that selects the
+// image-strip frame).  The numeric-id read crashed when the AUDIO_FIDELITY rows
+// (ReportLeak et al., cc2b109) grew the chained tables: index 3 landed on a
+// scalar, the resolve walked garbage, and the gauge background pass AV'd
+// (BT_DEV_GAUGES=1, the pod launch flag).  House rule (gotcha 8): named members
+// via a complete-type TU -- never a raw numeric attribute index.
+//===========================================================================//
+int BTCoolingLoopFrame(void *subsystem_v)
+{
+	Subsystem *sub = (Subsystem *)subsystem_v;
+	if (sub == 0 || !sub->IsDerivedFrom(*HeatSink::GetClassDerivations()))
+		return 0;
+	HeatSink *sink = (HeatSink *)sub;
+	if (sink->coolantAvailable != 1)					// the binary's src+0x134 gate
+		return 0;
+	Subsystem *master = sink->linkedSinks.Resolve();	// attr id 3 "HeatSink" + FUN_00417ab4
+	if (master == 0 || !master->IsDerivedFrom(*Condenser::GetClassDerivations()))
+		return 0;
+	return ((Condenser *)master)->condenserNumber;		// master+0x1d4 (loop/frame number)
+}