Issue #31: wire the EJECT button (EjectAmmo msg 0xb @004bb9b8) -- the in-mission unjam

Disasm-faithful transcription of the export-gap handler onto
ProjectileWeapon (MESSAGE_ENTRY id 0xb, the #19 pattern).  PRESS arms
the ~3s UpdateEject countdown (bin alarm -> Ejecting(3); gate 2 parks
the weapon offline mid-eject -- authentic).  HOLD to completion =
DumpAmmo jettisons the bay -> NoAmmo.  TAP (release early) cycles ONE
round out via FeedAmmo and returns the weapon to Loading -- clears a
jam at the cost of a round (and recovers a FailureHeat 7 while rounds
remain).  Binary structure kept exactly incl. the press-no-bin
fall-through into the release block.

AmmoBin: Ejecting(3)/Ejected(4) alarm levels decoded + named
SetAmmoState accessor (databinding rule).  Always-on forensics:
'[weap] EJECT tap' + '[ammo] bay DUMPED overboard (N rounds)'.

Rig-verified live (BT_EJECTTEST=1 / =hold on LRM15): taps eject one
round each and return the weapon to service (15->8 across cycles);
hold dumps all 16 -> NoAmmo.  Awaiting a human press of the actual
ENG-page button on a jammed weapon.

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

game/reconstructed/projweap.cpp

@@ -169,11 +169,21 @@ Derivation
 	);
 
 // task #6: inherit MechWeapon's handler set (see emitter.cpp note).
+// issue #31 (2026-07-23): register the ammo-weapon handler table @0x512210
+// {0xb, "EjectAmmo" -> @004bb9b8} on top of MechWeapon's ids 9/10 -- the pod's
+// EJECT button (tap = eject one round / unjam, hold = jettison the bay) was
+// silently swallowed.  (The energy-weapon branch binds 0xb to ToggleSeekVoltage
+// in ITS table instead -- see emitter.cpp.)
 Receiver::MessageHandlerSet&
 	ProjectileWeapon::GetMessageHandlers()
 {
+	static const Receiver::HandlerEntry entries[]=
+	{
+		MESSAGE_ENTRY(ProjectileWeapon, EjectAmmo)		// id 0xb  @004bb9b8
+	};
 	static Receiver::MessageHandlerSet messageHandlers(
-		MechWeapon::GetMessageHandlers());				// copy-inherit
+		ELEMENTS(entries), entries,
+		MechWeapon::GetMessageHandlers());				// copy-inherit (ids 9/10)
 	return messageHandlers;
 }
 Simulation::AttributeIndexSet	ProjectileWeapon::AttributeIndex;
@@ -495,6 +505,63 @@ void
 	}
 }
 
+//
+// @004bb9b8 -- the EJECT button (ammo-weapon handler table @0x512210, id 0xb).
+// Disasm-transcribed 2026-07-23 (the fn sits in a Ghidra export gap; issue
+// #31).  PRESS (data > 0, bin resolved): bin alarm -> Ejecting(3), reset the
+// countdown, ejectState = 0 (UpdateEject runs it; hold ~3s to completion =
+// DumpAmmo whole bay -> NoAmmo).  RELEASE with the countdown still live (a
+// TAP): bin alarm Ejected(4) -> Loaded(1), FeedAmmo cycles ONE round out;
+// bay dry -> weapon NoAmmo(7), else weapon -> Loading(3) + full recoil -- the
+// weapon RETURNS TO SERVICE (this is the in-mission UNJAM; it also recovers a
+// FailureHeat 7 while rounds remain).  Binary structure kept exactly: a press
+// with NO bin falls THROUGH to the release block (jle/je both target 4bba29).
+//
+void
+	ProjectileWeapon::EjectAmmoMessageHandler(ReceiverDataMessageOf<int> *message)
+{
+	if (MechSubsystem::IsDamaged())							// @4ac9c8 -- NOVICE lockout bridge
+		return;
+
+	AmmoBin *bin = (AmmoBin*)ammoBinLink.Resolve();			// FUN_00417ab4(this+0x43c)
+
+	if (message->dataContents > 0 && bin != 0)				// PRESS @4bb9d0/4bb9e9
+	{
+		bin->SetAmmoState(AmmoBin::Ejecting);				// SetLevel(bin+0x194, 3)
+		timeToEject		= totalTimeToEject;					// this+0x3f4 = this+0x3f0
+		percentOfEject	= 0.0f;								// this+0x3f8
+		ejectState		= 0;								// this+0x400 -- countdown live
+		return;												// jmp 4bbad9
+	}
+
+	// RELEASE (or press-no-bin fall-through) @4bba29
+	if (ejectState == 0)									// countdown still live -> a TAP
+	{
+		if (bin != 0)
+		{
+			bin->SetAmmoState(AmmoBin::Ejected);			// SetLevel(bin+0x194, 4)
+			bin->SetAmmoState(AmmoBin::Loaded);				// SetLevel(bin+0x194, 1)
+			bin->FeedAmmo();								// @4bd4f4 -- cycle one round out
+			if (bin->GetAmmoState() == AmmoBin::Empty)		// [bin+0x1a8] == 2
+				weaponAlarm.SetLevel(NoAmmoState);			// bay dry -> 7
+			else
+			{
+				weaponAlarm.SetLevel(3);					// -> Loading: BACK IN SERVICE
+				recoil = rechargeRate;						// this+0x3e8 = this+0x3dc (dial restarts)
+			}
+			DEBUG_STREAM << "[weap] " << GetName() << " EJECT tap: round out, "
+				<< bin->GetAmmoCount() << " left -> "
+				<< (bin->GetAmmoState() == AmmoBin::Empty ? "NoAmmo" : "reloading")
+				<< "\n" << std::flush;
+			timeToEject		= totalTimeToEject;
+			percentOfEject	= 0.0f;
+		}
+		else
+			weaponAlarm.SetLevel(NoAmmoState);				// @4bbabe -> 7
+	}
+	ejectState = -1;										// @4bbacf -- countdown cancelled
+}
+
 //
 // @004bbc78 -- bleed the firing charge (MechWeapon recoil @0x3E8) at a rate set
 // by the available bus voltage and the AmmoBin's remaining supply ratio.