ci: build Windows ARM64 with Visual Studio 2026

.github/workflows/native_release.yml

@@ -697,7 +697,7 @@ jobs:
             backend_glob: "*ggml-blas*.dll"
           - arch: arm64
             vcpkg_triplet: arm64-windows
-            runs_on: windows-11-arm
+            runs_on: windows-11-vs2026-arm
             backend: vulkan
             include_core: true
             needs_cuda: false
@@ -706,7 +706,7 @@ jobs:
             backend_glob: "*ggml-vulkan*.dll"
           - arch: arm64
             vcpkg_triplet: arm64-windows
-            runs_on: windows-11-arm
+            runs_on: windows-11-vs2026-arm
             backend: blas
             include_core: false
             needs_cuda: false

.github/workflows/validate_wrapper.yml

@@ -134,7 +134,7 @@ jobs:
   windows-arm64-kleidiai:
     needs: changes
     if: needs.changes.outputs.native == 'true'
-    runs-on: windows-11-arm
+    runs-on: windows-11-vs2026-arm
     timeout-minutes: 30
     strategy:
       fail-fast: false

CMakePresets.json

@@ -175,7 +175,7 @@
       "name": "windows-arm64-full",
       "inherits": "windows-base",
       "binaryDir": "${sourceDir}/build/wa64",
-      "generator": "Visual Studio 17 2022",
+      "generator": "Visual Studio 18 2026",
       "architecture": {
         "value": "ARM64",
         "strategy": "set"

docs/platform_backend_strategy.md

@@ -69,6 +69,14 @@ The Android artifact check is `tools/validate_android_cpu_isa.py --help`.
   - `third_party/opencl-stubs/`
   - auto-built OpenCL ICD loader from `third_party/OpenCL-ICD-Loader` + `third_party/OpenCL-Headers`
 - Linux arm64 builds on x64 runners require `aarch64-linux-gnu-gcc/g++`, `libopenblas-dev:arm64`, and `libvulkan-dev:arm64`.
+- Windows ARM64 uses the `Visual Studio 18 2026` generator (CMake >= 4.2) with
+  the ClangCL toolset. CI pins the `windows-11-vs2026-arm` runner because the
+  `windows-11-arm` label moved to that image in September 2026
+  (actions/runner-images#14602), and that image has no VS 2022 instance.
+  `tools/build.py windows --arch arm64` therefore needs VS 2026. With only
+  VS 2022 installed, configure directly with
+  `cmake --preset windows-arm64-full -G "Visual Studio 17 2022"` in a fresh
+  build directory.
 - Windows MSVC builds disable IPO/LTCG for `llama-common` and `mtmd` by default.
   Current MSVC `link.exe` can access-violate when linking the large
   `llama-common` utility DLL with `/LTCG`. CMake's automatic Windows export