fix: default distributions to automatic GPU support with CPU fallback

crates/searchi-semantic/native/CMakeLists.txt

@@ -10,12 +10,12 @@ endif()
 set(BUILD_SHARED_LIBS OFF CACHE BOOL "Static local worker runtime" FORCE)
 set(GGML_OPENMP OFF CACHE BOOL "Use bounded native llama thread pools without external OpenMP runtime" FORCE)
 set(GGML_NATIVE OFF CACHE BOOL "Portable CPU kernels")
-# GPU backends are explicit production build options. The Windows VM builds
-# with all of these OFF; runtime device selection always retains CPU fallback.
+# Normal distribution builds include GPU support and CPU fallback. CPU-only
+# configuration is explicitly reserved for development/testing in the VM.
 set(GGML_CUDA OFF CACHE BOOL "Production CUDA backend")
 set(GGML_VULKAN OFF CACHE BOOL "Production Vulkan backend")
 set(GGML_METAL OFF CACHE BOOL "Production Metal backend")
-set(SEARCHI_ACCELERATION "cpu" CACHE STRING "cpu, auto, metal, vulkan, or cuda")
+set(SEARCHI_ACCELERATION "auto" CACHE STRING "auto; explicit developer overrides: cpu, metal, vulkan, cuda")
 if(SEARCHI_ACCELERATION STREQUAL "cpu")
     set(GGML_CUDA OFF CACHE BOOL "CPU test build" FORCE)
     set(GGML_VULKAN OFF CACHE BOOL "CPU test build" FORCE)
@@ -27,12 +27,10 @@ elseif(SEARCHI_ACCELERATION STREQUAL "cuda")
 elseif(SEARCHI_ACCELERATION STREQUAL "vulkan")
     set(GGML_VULKAN ON CACHE BOOL "Production Vulkan backend" FORCE)
 elseif(SEARCHI_ACCELERATION STREQUAL "auto")
-    find_package(Vulkan QUIET)
-    if(Vulkan_FOUND)
-        set(GGML_VULKAN ON CACHE BOOL "Available production Vulkan backend" FORCE)
-    else()
-        message(STATUS "No production acceleration SDK detected; retaining CPU backend")
-    endif()
+    # A missing build SDK must not silently turn a normal release into a
+    # CPU-only artifact. End users need drivers, not this compilation SDK.
+    find_package(Vulkan COMPONENTS glslc REQUIRED)
+    set(GGML_VULKAN ON CACHE BOOL "Production GPU support with runtime CPU fallback" FORCE)
 else()
     message(FATAL_ERROR "Unknown SEARCHI_ACCELERATION=${SEARCHI_ACCELERATION}")
 endif()