build: package universal Windows runtime and verify automatic CPU fallback

docs/SEMANTIC.md

@@ -40,6 +40,13 @@ must have the relevant compilation SDK. Missing Vulkan/glslc now fails the
 normal build rather than silently omitting acceleration. Actual GPU parity,
 loader/dependency packaging and no-driver CPU fallback still require evidence.
 
+Windows x64 build scripts provision the pinned official Vulkan SDK locally,
+verify its provenance and stage the app-local loader with its notice. Forced
+CPU startup disables Vulkan registration before the backend registry initializes;
+CPU contexts disable device-operation offload. Automatic startup transport
+failure now restarts once on CPU without weakening model/protocol validation.
+GPU inference failure also retains the bounded existing CPU retry.
+
 | Artifact | Bytes | SHA256 |
 | --- | ---: | --- |
 | embeddinggemma-2-Q8_0.gguf | 309,855,456 | 2188ac1deca4b77dffefd603c2776a9d76d9d74ec01841392982ebb840b09135 |