fix(darwin): fix vibevoice-cpp build linkage + fail-safe go backend packaging (#10276)

* fix(darwin): never package a go backend build tree as a working image

The darwin/arm64 vibevoice-cpp image shipped the source tree with a
half-built CMake directory (build-libgovibevoicecpp-fallback.so/) and no
backend binary, so the backend could never start: run.sh exec'd a
vibevoice-cpp binary that was not in the package and LocalAI timed out
waiting for the gRPC service.

Two durable, backend-agnostic defenses:

- backend/go/vibevoice-cpp/Makefile: mirror whisper's cleanup discipline so a
  partial CMake tree cannot survive into packaging. Run `make purge` before
  each variant build and `rm -rfv build*` after. The old recipe only removed
  its build dir after a successful `mv`, so a failed build left the half-built
  tree behind.

- scripts/build/golang-darwin.sh: before creating the OCI image, remove any
  stray build-* directory and assert that the binary run.sh launches actually
  exists. A build that produced no binary now fails the job loudly instead of
  publishing a source tree as a working backend. The binary name is derived
  from run.sh's `exec $CURDIR/<binary>` line (parakeet-cpp launches
  parakeet-cpp-grpc, so it is not always ${BACKEND}) with a ${BACKEND}
  fallback.

The underlying native build failure that left vibevoice-cpp half-built still
needs to be reproduced and fixed on Apple Silicon; this change ensures such a
failure can never again be published as a working image.

Refs #10267

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: Claude:claude-opus-4-8 [Claude Code]

* fix(vibevoice-cpp): build libvibevoice.a on darwin (link target, not path)

The darwin build failed with:

    No rule to make target 'vibevoice/libvibevoice.a', needed by
    'libgovibevoicecpp.so'.  Stop.

The upstream vibevoice project is added with add_subdirectory(... EXCLUDE_FROM_ALL),
so its `vibevoice` static-library target is only built when something links it
as a target. The Apple branch linked only `$<TARGET_FILE:vibevoice>` - a bare
archive path with no target reference - so CMake never emitted a rule to build
libvibevoice.a, while the Linux branch worked because it passes the `vibevoice`
target name inside the --whole-archive flags.

Link the `vibevoice` target on Apple (establishing the build dependency) and
apply -force_load as a separate link option to keep whole-archive semantics so
purego can dlsym the vv_capi_* symbols.

Refs #10267

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: Claude:claude-opus-4-8 [Claude Code]

---------

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>

scripts/build/golang-darwin.sh

@@ -5,6 +5,28 @@ export BUILD_TYPE="${BUILD_TYPE:-metal}"
 mkdir -p backend-images
 make -C backend/go/${BACKEND} build
 
+BACKEND_DIR="backend/go/${BACKEND}"
+
+# Never package a stray CMake build tree (e.g. build-libgo*-*.so/, a directory
+# left behind by a partial native build) into the backend image.
+rm -rf "${BACKEND_DIR}"/build-*
+
+# Fail loudly if the build did not produce the backend binary, instead of
+# silently packaging the source/build tree as a "backend" that can never start
+# (issue #10267: the darwin vibevoice-cpp image shipped sources, no binary).
+# run.sh's final `exec $CURDIR/<binary>` is the contract for what gets launched;
+# the binary is not always named after the backend (e.g. parakeet-cpp launches
+# parakeet-cpp-grpc), so derive it from run.sh and fall back to ${BACKEND}.
+RUN_BINARY=""
+if [ -f "${BACKEND_DIR}/run.sh" ]; then
+        RUN_BINARY=$(grep -oE '\$CURDIR/[A-Za-z0-9._-]+' "${BACKEND_DIR}/run.sh" | grep -v 'ld\.so' | tail -1 | sed 's|\$CURDIR/||')
+fi
+RUN_BINARY="${RUN_BINARY:-${BACKEND}}"
+if [ ! -x "${BACKEND_DIR}/${RUN_BINARY}" ]; then
+        echo "ERROR: ${BACKEND_DIR}/${RUN_BINARY} not found after build; refusing to package a broken backend image (see issue #10267)." >&2
+        exit 1
+fi
+
 PLATFORMARCH="${PLATFORMARCH:-darwin/arm64}"
 IMAGE_NAME="${IMAGE_NAME:-localai/${BACKEND}-darwin}"