docs(site): publish llama.cpp runtime v0.2.3 matrix

[LauraGPT]

Summary

• publish the verified v0.2.3 nine-platform download matrix and SHA-256 values
• link exact release/workflow evidence and document post-backend diagnostic boundaries
• preserve the explicit AMD Windows and Android/Mali support limits

Verification

• Python product-site suite: 92 passed
• product-site build: 27 pages; validator: 106 pages
• Playwright full suite: 26 passed on mobile and desktop
• release assets independently downloaded and matched to workflow artifacts and GitHub digests