#468 v0.1.34 Windows AMD (discrete W7900): crash 0xC0000005 on first request — engine loads the driver's System32 amdhip64_7.dll

Descripción

**What happens**
Fresh clone of v0.1.34, set up with `START-HERE.bat --setup --backend hip --low-ram on`. The engine loads fine (all 24,576 experts in the GPU cache), then crashes on the very first request with exit code 3221225477 (0xC0000005). It happens every time, on every model.

**Cause**
The crash is inside `C:\WINDOWS\SYSTEM32\amdhip64_7.dll` (the AMD driver's HIP runtime, 10.0.3683.0), called from the bundled `engine\rocm\bin\rocblas.dll` via `hipblasGemmEx`. Windows' DLL search order picks the driver's System32 runtime ahead of the bundled ROCm, so the bundled rocBLAS/hipBLAS run on a mismatched HIP runtime.

Stack (top):
    #0  amdhip64_7.dll+0x2d874a (C:\WINDOWS\SYSTEM32)
    #6  rocblas_zgemv (engine\rocm\bin\rocblas.dll)
    #11 rocblas_gemm_ex
    #12 hipblasGemmEx (engine\rocm\bin\hipblas.dll)
    #13 strata.exe+0x1899da

**Workaround (confirmed)**
Copying a matching `amdhip64_7.dll` (ROCm 10.2 nightly, 10.0.3686.0) into `engine\` next to `strata.exe` makes Windows load it instead of the System32 copy. The crash is gone and everything works.

Suggested fix: ship the matching `amdhip64_7.dll` next to `strata.exe`, or load it by full path (LoadLibraryExW) at startup before any ROCm library, so the driver's copy can't win.

**Results after the workaround (discrete-card data point)**
- Q2_0, 256K context, 8-bit KV, low-RAM mode: 24,576 experts in VRAM, 100% decode hit rate
- 102.5 tok/s decode on a 513-token answer (6.2 s total)
- System RAM in use: 13.3 of 48 GB
- Clearly faster than the earlier jagsan-cyber `win-hip-gfx1201` branch on the same PC (about 80 tok/s, about 43 GB RAM)

**Also seen**
- The PCIe probe reports impossible bandwidth (about 6,600 to 73,000 GB/s host->device across runs) and always falls back to the 0.55 default.

**Setup**
- Strata v0.1.34 (1678de3)
- GPU: AMD Radeon PRO W7900, 48 GB, gfx1100 (discrete)
- AMD driver: 32.0.32015.2008 (9/28/2026)
- CPU: Intel i5-13600K (AVX2, no AVX-512)
- RAM: 48 GB
- OS: Windows 11