BT410 Phase 5.3.18: flying missiles -- spawn/home/detonate LIVE, teardown open

The Missile entity family is reconstructed: Projectile : Mover gets a real
make-path ctor; Missile hosts the Seeker + MissleThruster roster (the
AUTHENTIC surviving SEEKER.HPP / MISTHRST.HPP interfaces -- the 1995
misspelling included) and flies the binary's guided integrator (@004bef78):
age/lifetime, seeker re-lead with the decoded loft constants
(200/50/300/0.1), thruster burn, steering (gain 4.0, deadband 1e-4), and
the proximity fuse delivering the cluster damage ONCE with the launcher as
inflictor.  Live-verified end-to-end: LAUNCH -> flight telemetry (thruster
visibly accelerating) -> DETONATE on the target ~0.9s out.

OPEN: the first ~Missile off the death row completes, then the frame
page-faults with EIP in the heap -- the first entity/subsystem teardown the
reconstructed sim has ever run.  The spawn path is therefore OPT-IN
(BT_MISSILE_FLIGHT=1); default SRM delivery stays the 5.3.18a instant-hit
cluster (verified 1:1, zero exceptions).  Forensics + engine truths
(SearchList crashes on non-directory ids; MakeMessages need FAMILY resource
ids; explosionModelFile is a model-list INDEX) in MISSILE.NOTES.md.

Also fixed on the way: the Subsystem NAME ctor left damageZone
UNINITIALIZED (latent garbage for every name-built subsystem).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

restoration/source410/MUNGA/SUBSYSTM.CPP

@@ -79,6 +79,12 @@ Subsystem::Subsystem(
 	Register_Pointer(subsystemName);
 	Str_Copy(subsystemName, subsystem_name, name_size);
 	segmentIndex = -1;
+	//
+	// (Was UNINITIALIZED in this ctor variant only -- the resource ctor
+	// NULLs it.  Garbage here is a latent crash for any name-built
+	// subsystem whose dtor path or damage query walks the zone pointer.)
+	//
+	damageZone = NULL;
 }
 
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