GPU tests build their designs with SMLib, and the GPU jobs fetch it

The GPU path tests (and the Windows FXC job, cargo test -p solidcraft-gpu) build real
designs through solidcraft-engine, a dev-dependency without its smlib feature. Run on
their own (-p solidcraft-gpu), nothing in the build turns SMLib on, so every geometric
step answered "this build has no SMLib" (10 path::* tests on develop). The
dev-dependency now asks for engine/smlib, as the apps do, and both jobs fetch SMLib
before building.

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

.github/workflows/ci.yml

@@ -593,6 +593,9 @@ jobs:
         with:
           key: native-gpu
           save-if: ${{ (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/develop') && matrix.shard == 1 }}
+      - name: Fetch SMLib (crates/smlib/SMLIB_REV)
+        shell: bash
+        run: scripts/fetch-smlib.sh
       - name: Set up compiler cache
         uses: mozilla-actions/sccache-action@fc920bf0ec8de6ee65d409111f7ec508035751ba # v0.0.11
         with:
@@ -846,6 +849,9 @@ jobs:
         with:
           key: windows-fxc
           save-if: ${{ github.ref == 'refs/heads/main' || github.ref == 'refs/heads/develop' }}
+      - name: Fetch SMLib (crates/smlib/SMLIB_REV)
+        shell: bash
+        run: scripts/fetch-smlib.sh
       # One test at a time: WARP's shader JIT crashes now and then (a null read in
       # d3d10warp.dll's JIT optimizer, about 1 run in 60) when several devices compile compute
       # pipelines at once, which the parallel tests do. Minidumps showed it in WARP itself, not

crates/gpu/Cargo.toml

@@ -26,8 +26,9 @@ wgpu = { workspace = true, features = ["metal", "vulkan", "dx12", "gles"] }
 [dev-dependencies]
 image = { workspace = true }
 solidcraft-kernel = { workspace = true }
-# Headless pictures of real designs (capture tests).
-solidcraft-engine = { workspace = true, features = ["bundled-render-library"] }
+# Headless pictures of real designs (capture tests), built by the real kernel: SMLib
+# (scripts/fetch-smlib.sh), as in the apps.
+solidcraft-engine = { workspace = true, features = ["bundled-render-library", "smlib"] }
 solidcraft-io = { workspace = true }
 serde_json = { workspace = true }
 # The HLSL the D3D12 backend compiles (tests check it suits FXC).