feat(nescapture): open the capture layer

A Vulkan implicit layer that captures frames from inside the workload's own
process and encodes them on the GPU they were drawn on. Fourth and last of this
batch, imported as a tree from `nestrilabs/nescapture` on the same terms.

Filed under `apps/` rather than `crates/` despite building a cdylib. The rule
here is what a thing *is*, not what it compiles to: this is a finished artefact
that gets installed into an image beside its layer manifest, not a library
another crate in this tree depends on. `crates/` is for the latter, and putting
this there would make the distinction useless the first time someone looked.

Wired to the workspace, `nesprotocol` by path. Its description named the
transport component; that reads better as what it actually is — where the frames
go — so it says that instead.

Whole workspace builds and tests: 21 across four members.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -13,6 +13,7 @@
 [workspace]
 resolver = "3"
 members = [
+  "apps/nescapture",
   "apps/nescope",
   "apps/neswire",
   "crates/nesprotocol",