ISO payload: Qwen3.5-2B distill

Not a kernel release. This holds the ISO payload for the Qwen3.5-2B distill so CI can build install media without the weights living in the repository.

Contents go to \GLADOS\ on the ISO: the converted checkpoint, its tokenizer, the root certificate bundle and the licence.

Apache-2.0, LICENSE.TXT included, confirmed with the distill's creator.

model.bin here is canonical at seq_len 512. The release workflow stamps the context window it wants with tools/ctxstamp.py, which writes one i32 at offset 36 and reads it back through v4.py. Stamping 512 to 32768 produces a file byte-identical to a full convert.py run at that seq, so N context variants cost one upload and N stamps rather than N copies of the same 1.8 GB.

Digests are in payload/q35-2b.txt and the workflow verifies against them BEFORE stamping, since stamping changes four bytes and a digest taken afterwards could never match.

roots.der is built from a Windows certificate store by scripts/fetch-roots.ps1 and cannot be regenerated on a Linux runner, which is why it is pinned rather than rebuilt.