gauge wave P2b: build the Comm KILLS/DEATHS pilot roster (PilotList)

PilotList (keyword "pilotList") was PROSE-ONLY, so the Comm surface showed only
the baked btcomm.pcx labels.  Reconstructed all 7 functions from part_014.c:
3156-3434 (Make/ctor/dtor/BecameActive/TestInstance/Execute/DrawMechIcon), with
the 8x(x,y,layoutMode) layout table DAT_0051af88 PE-parsed exact from BTL4OPT.EXE.
Draws ONE roster slot/frame (round-robin) from the viewpoint mech's cockpit-mapper
pilot roster.

- Roster FEED: new BTResolveRosterPilot(slot) bridge in mechmppr.cpp (a complete-Mech
  TU) resolves the viewpoint mech's ControlsMapper (subsystemArray[0]) -> GetPilot;
  btl4gau3.cpp reads the returned pilot at raw BTPlayer offsets.  The mapper's
  FillPilotArray already fills the roster (pilotArray[0]=GetMissionPlayer,
  [1..]=FindGroup("Players")).
- KILLS = killCount@0x27c (real; ScoreMessageHandler increments it in combat).
- DEATHS: the binary reads pad_0x280 which has NO writer anywhere (a shipped dead
  field -> perpetual 0).  FIX per "if it doesn't work, fix it": read the real
  deaths counter Player::deathCount@0x200 (VehicleDeadMessageHandler increments it)
  so DEATHS is meaningful in MP.
- DrawMechIcon: App+0xC8 name-bitmap cache is unwired (same deferral PlayerStatus
  uses) -> LookupPlayerNameBitmap returns NULL -> the tinted name box (never an AV).

Dropped the bogus x,y from the header ctor (positions come from DAT_0051af88).
/FORCE-safe (all vtable slots real; link log clean, no unresolved PilotList/
BTResolveRosterPilot).  Verified DBASE+dev gauges: the Comm surface now renders the
live local pilot row (KILLS 0 DEATHS 0 + name box; 0/0 authentic in solo -- the
combat scoring feed that moves them is Phase 3), combat un-regressed (DESTROYED),
0 crashes.

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

game/reconstructed/mechmppr.cpp

@@ -1177,3 +1177,29 @@ void
 	MechControlsMapper::NotifyOfDisplayModeChange(int /*new_mode*/)
 {
 }
+
+//
+// gauge wave P2: BTResolveRosterPilot -- the bridge PilotList (btl4gau3.cpp, the
+// Comm KILLS/DEATHS roster) uses to read the viewpoint mech's pilot roster.  The
+// roster lives on the mech's ControlsMapper (subsystemArray[0]); this complete-Mech
+// TU resolves it, PilotList reads the returned pilot at raw BTPlayer offsets.
+// Faithful to the binary's Execute: **(App+0x6c mech +0x128)[slot] -> GetPilot.
+//
+void *BTResolveRosterPilot(int slot)
+{
+	if (application == 0)
+	{
+		return 0;
+	}
+	Mech *mech = (Mech *)application->GetViewpointEntity();		// App+0x6c local mech
+	if (mech == 0 || mech->GetSubsystemCount() < 1)
+	{
+		return 0;
+	}
+	MechControlsMapper *mapper = (MechControlsMapper *)mech->GetSubsystem(0);	// subsystemArray[0]
+	if (mapper == 0)
+	{
+		return 0;
+	}
+	return (void *)mapper->GetPilot(slot);						// FUN_004b0898
+}