Repin local llama runtime to b10068
Repin bundled llama.cpp from b9291 to b10068 for macos-arm64, ubuntu-vulkan-x64, and ubuntu-vulkan-arm64 with the verified artifact digests.
Rebase floor-tier Qwen residency from 4541 to 4137 MiB (measured 4130 MiB + 7 MiB cushion). This drops the Parakeet co-location requirement from 8512 to 8108 MiB, so 8 GiB cards (8192 MiB) now flip from CPU transcription to GPU transcription. The requirement still emerges from the tier constant; parakeet_placement.py arithmetic is unchanged.
Consolidate pin assertions into one version-neutral test covering all three complete tag/filename/digest triples; the aarch64-linux digest was previously asserted nowhere. Add a fail-closed installer test proving sha256 mismatch aborts before extraction, and cover the capable-tier Vulkan launch argument vector in addition to the floor tier.
Repair tests/eval_schemas.py by dropping the removed provider= kwarg and gating on the active-brain resolver. Serving topology, context tiers, request params, Flash Attention, and F16 KV remain unchanged.