fix(release): complete hosted binary validation

[localai-bot]

Completes the hosted release validation exposed by the full eight-bundle dry run.

• keeps native Metal packaging compatible with macOS system Bash
• resolves the external CUDA driver stub only while validating GPU-less archives
• installs a SHA256-pinned Intel SDE rich runner for all x86 tiers
• retains QEMU for feature-poor baseline and refusal proof
• mounts the same rich runner into the literal-static musl lane
• runs full conformance on rich tiers and a targeted real GEMM on poor emulation

Verification:

• full agent preflight green
• 24 focused release tests green
• full 686-assertion AVX-512 suite green under Intel SDE
• QEMU portable execution and unsupported-tier refusal green
• release workflow policy and shell syntax green