[hzqst]

When RenderStateCache serializes a PSO using device shaders, it reconstructs ShaderCreateInfo from their WGSL but leaves EntryPoint at its default "main". Shaders with valid entry points such as vertexMain, fragmentMain, or computeMain then fail reflection and PSO archiving. This also affects shaders restored from an existing shader archive. A ready device PSO does not prove archiving succeeded because the cache catches serialization exceptions.

Changes

• Expose the existing backend GetEntryPoint() through IShaderWebGPU, returning the actual selected WGSL entry point.
• Add GetWebGPUShaderEntryPoint() using the existing WebGPU utility pattern, including a stub for builds without WebGPU.
• Restore that entry point when RenderStateCache reconstructs the shader creation info for serialization. The archive format already stores entry points and requires no changes.
• Add four WebGPU regression tests covering single-entry and multi-entry WGSL, both device-created shaders and shaders restored from a shader-only archive. Each test exercises non-main vertex, fragment, and compute entry points, stores the resulting PSOs, destroys and recreates the cache, and requires archive hits with ready pipelines. Multi-entry modules place an unused entry point of the same stage first and give it additional resources; the restored pipeline must preserve the selected entry point's resource layout.

Validation

Windows x64 Debug, NVIDIA GPU:

• Before the production fix, all four initial regression tests failed with Entry point 'main' is not found, shader serialization errors, and missing PSO archive hits. The archive-restored cases first logged successful shader archive hits, reproducing the reported sequence.
• WebGPU build succeeded. RenderStateCacheTest.*, ArchiveTest.WGSLEntryPointRemapping, and ShaderCreationTest.WGSLEntryPointRemapping: 34 passed, 5 skipped, 0 failures, including all four final regression tests.
• Build with WebGPU disabled succeeded. Vulkan RenderStateCacheTest.*: 31 passed, 6 skipped, 0 failures.
• Repository clang-format 10 validation passed for all seven changed files; git diff --check passed.

Run the API tests from Tests/DiligentCoreAPITest/assets:

DiligentCoreAPITest.exe --mode=wgpu --gtest_filter=RenderStateCacheTest.*:ArchiveTest.WGSLEntryPointRemapping:ShaderCreationTest.WGSLEntryPointRemapping
DiligentCoreAPITest.exe --mode=vk --gtest_filter=RenderStateCacheTest.*

The regressions recreate caches and reload archives on the same device. A full application restart/device recreation and the original HLND2T scenario were not run.

Compatibility

Adding a virtual method to IShaderWebGPU changes its C++ vtable; consumers and implementations must be rebuilt together. The archive format is unchanged.

Closes #813