fix(rt): rebuild TLASes in place, after earlier traces, and queue their handles like a Mesh's

BuildTLAS
- A rebuild for a new instance count or build preference used to create a
  new acceleration structure and destroy the old one at once, though the
  command buffer being recorded could still use it (a scene and then a
  model built in one setup). The acceleration structure now spans its whole
  storage buffer, and a rebuild that fits builds into it again, so the
  handle and tlases[i].address stay the same and nothing is destroyed. A
  TLAS that outgrows its storage gets new storage and a new handle; the old
  handle goes to the deletion queue ahead of the storage it lives in. It is
  queued after the scratch is resized, and its address goes with it, so a
  Resize or create that throws leaves no address of a queued acceleration
  structure behind.
- The barrier before the build also orders earlier traces and compute ray
  queries of the TLAS, which a refit or a rebuild in place would otherwise
  overwrite while they read it (BuildTlasWriteBarrier). Its source access
  mask holds no read bit: one does nothing, but makes synchronization
  validation 1.4.363 report the second of two builds in one command buffer
  as a write-after-write hazard.
- TlasReadBarrier is now TlasBarrier, shared by both barriers.
- Documented: call BuildTLAS once every earlier submission that used
  tlases[index] has completed, and when the address stays the same.

TlasWithBuffer
- Moves hand the acceleration structure over, and destroying or assigning
  over one queues it ahead of its storage. The implicit members dropped the
  handle over freed storage, or left two owners and a moved-from TLAS that
  refit through buffers it no longer had.

Tests
- TLASLifetime: destroying, moving, move-assigning and resetting a
  TlasWithBuffer.
- TLASHighWaterMark skips without ray tracing. It asserts the acceleration
  structure is rebuilt in place on a shrink or a growth within capacity,
  that the old handle is queued before its storage on a growth past it, and
  that builds in one command buffer keep the handle while they fit, queue
  it once when one outgrows the storage, and free it only on its retire
  frame.
- TLASBuildBarrier checks the barrier before the build too.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

project.cpp

@@ -437,16 +437,27 @@ extern "C" Configuration CrafterBuildProject(std::span<const std::string_view> a
         // instance counts — and asserts that a shrink (and any growth within
         // the high-water capacity) reuses the existing allocation while a
         // growth past it reallocates, with the validation layer reporting no
-        // errors when an oversized instance buffer is fed to the build. Needs a
-        // Vulkan RT device at runtime, so it shares the native build settings.
+        // errors when an oversized instance buffer is fed to the build. The
+        // acceleration structure follows the same high-water mark: a rebuild
+        // that fits its storage builds into the same handle. Needs a Vulkan
+        // RT device at runtime, so it shares the native build settings.
         cfg.tests.push_back(LibraryTest("TLASHighWaterMark"));
 
-        // The barrier BuildTLAS records after the build carries the
+        // The barriers BuildTLAS records around the build: the one before it
+        // orders earlier builds, traces and compute ray queries before the
+        // build overwrites the TLAS, and the one after it carries the
         // acceleration-structure memory dependency to the shaders that read
-        // the TLAS, not just execution order. BuildTlasReadBarrier is pure
-        // CPU logic, so no GPU device is needed at runtime.
+        // the TLAS, not just execution order. BuildTlasWriteBarrier and
+        // BuildTlasReadBarrier are pure CPU logic, so no GPU device is needed
+        // at runtime.
         cfg.tests.push_back(LibraryTest("TLASBuildBarrier"));
 
+        // A TlasWithBuffer queues its acceleration structure for deferred
+        // deletion, ahead of its storage, when it is destroyed or assigned
+        // over, and moving one hands the acceleration structure over.
+        // Headless; needs a Vulkan RT device at runtime, like MeshLifetime.
+        cfg.tests.push_back(LibraryTest("TLASLifetime"));
+
         // BuildTLAS on an empty scene (no elements registered yet) builds a
         // valid empty TLAS instead of creating zero-size buffers, and adding
         // and removing instances afterwards still rebuilds it. Needs a Vulkan