Comprehensive layered architectural review covering all 109 crates,
306K LOC, 13,351 tests. Identifies 9 gaps (G0-G8) with the highest-
priority being 45 unimplemented! panics across rtx-backend-cuda/rocm/sycl
and the rtx-distributed workspace exclusion. Includes 17-item 4-phase
roadmap through 90 days.
Co-Authored-By: Claude Sonnet 4.6 <[email protected]>