v2.12.0 — conditional structural premises (MLA/PLE/MTP) as structuralAssumptions

What changed

• Attaches conditional structural premises to affected results as structuralAssumptions, an array of { id, statement }: mla-compressed-latent-cache, ple-llamacpp-non-gpu-residency, mtp-ordinary-generation. The same array is exposed by the CLI (--json, --top --json, --why, and a premise [id]: line in text mode), the composite Action output, and explain.
• Exact runtime caveat: each premise holds only under the pinned artifact/runtime path listed in the README section "Structural premises". For example, the PLE deduction applies only to the verified Gemma 4 e2b/e4b entries under the pinned llama.cpp/GGUF lazy-or-host-resident path; a runtime that loads PLE tensors onto the accelerator (vLLM, for example) invalidates that estimate. Unverified families keep their full weights GPU-resident (fail-closed), so a look-alike config cannot flip a verdict toward "fits".
• No speed claim. A premise states what the memory math assumes, not how fast the model runs. There is no runtime selector and no confidence score.
• Compatibility and shape preservation: unaffected results (plain GQA models such as Llama-3.1-8B-Instruct) carry no structuralAssumptions key, so legacy JSON shapes are unchanged. Existing JSON keys, --help, exit codes, conformance vectors, and census bytes are byte-identical to v2.11.0. The README Action reference moves to @v2.12.0.
• Test evidence: npm test 207/207, vectors/run.mjs 28/28, census:check byte-identical, tests written RED before the engine sync went GREEN, and a fixed-SHA cross-provider review of candidate 89a7ba3493cc8f17ae01988bad93249e4e4123a3 returned ACCEPT with P0=0 and P1=0. Released source is the squash merge ae5ec23dda523ea3d7de3cbbccdb8f70faeb1607 of PR #118 (byte-identical tree to the reviewed candidate). Refs #99.

Full diff: v2.11.0...v2.12.0