feat(quality): score every face on sharpness and alignment before it is evidence

Every embedding now carries the quality of the input it came from. Both
axes fall out of the AR-005 warp for free: crop_sharpness() is the
normalised Laplacian variance over the aligned 112x112, so contrast and
size cannot leak into it, and the alignment residual is the part of the
landmark deformation a similarity transform cannot explain, so in-plane
roll reads as zero and foreshortening does not.

Carried, not consumed. Nothing discounts or thresholds on either number
yet -- that is AR-030 and VR-012, and the knee has to be located against
recorded data before a gate is chosen. What this change buys is that the
data exists to locate it with.

No face is admitted unscored: the -1 sentinel is preserved rather than
clamped, and a degenerate landmark fit is counted rather than silently
dropped.

Takes the VR-001 dump to schema_version 2. The bump is not for readers,
which check for the datasets by name and replay a v1 dump unchanged; it
is so a consumer can tell "never scored" from "scored zero", which is
not recoverable from the arrays afterwards.

TRACES: AR-028, AR-029, AR-030 | VR-001 | SR-002

tests/CMakeLists.txt

@@ -25,6 +25,7 @@ add_executable(sae_tests
     test_face_detector_node.cpp
     test_scene_detector_node.cpp
     test_replay_fixtures.cpp
+    test_embedding_dump.cpp
     test_audio_signature.cpp
     ${CMAKE_SOURCE_DIR}/src/backends/gemm_backend.cpp
     ${CMAKE_SOURCE_DIR}/src/gallery/gallery_store.cpp