v0.32.12: qwen3.8: add renderer and MLX import support

Qwen3.8 keeps the Qwen3.5 model architecture and parser, but its chat template adds reasoning-effort and preserved-thinking semantics. Detect those template markers during safetensors import, select the qwen3.8 renderer, and cover thinking, tools, continuation, and malformed parser input.

Make indexed safetensors imports use the weight map's shard names instead of independently filtering files by the model-* convention. Reject unsafe shard paths, ignore unindexed tensors, and fail when an indexed weight is missing or stored in a different shard. Retain the conservative model-* scan when no index is present.

Treat Classification.Quantize as the effective tensor format and pass it to the manifest writer. This records file_type for automatic block-FP8-to-MXFP8 conversion and recognized prequantized inputs, preserves requested quantization and base-plus-draft behavior, and avoids claiming one type for mixed or unknown formats.

Normalize both supported convolution weight layouts with an explicit reshape. Add focused unit coverage for renderer selection, parser behavior, shard inventory, manifest metadata, and convolution layout; heavyweight reference-forward and release integration checks remain bring-up artifacts.