docs: record SmolLM2 Transformers compatibility

[RezaAshrafii]

Summary

Closes #4

• run the Transformers smoke test against HuggingFaceTB/SmolLM2-135M
• record the exact checkpoint revision, environment, configuration, and raw JSON result
• document verified, expected, and unsupported Transformers compatibility boundaries
• make no throughput or model-quality claim

Verification

• ruff check .
• ruff format --check .
• mypy src
• pytest -q (25 passed)
• uv build --offline

Smoke evidence

• Model revision: 93efa2f097d58c2a74874c7e644dbc9b0cee75a2
• Device: CPU
• Persistent budget: 64
• Recency buffer: 8
• Generated tokens: 128
• Eviction rounds: 9 per layer
• Raw result: results/smollm2-135m-smoke.json

The smoke result is compatibility and eviction-behavior evidence only. It is not a throughput comparison or model-quality evaluation.

[DaBestCode]

Maintainer review is positive. I verified the pinned SmolLM2 revision, checked the cache arithmetic (30 layers × 3 KV heads × 9 rounds = 810 head evictions), and ran the complete local suite: Ruff, formatting, mypy, 25 tests, and package build all pass.

The compatibility table correctly separates verified evidence from expected support, and the raw result makes no comparative performance or quality claim. No code changes are requested.

Because this PR is still a draft, please mark it ready for review when you consider it complete. I am approving the blocked Actions workflow now; once the hosted Python 3.10/3.13 matrix passes, this should be ready for formal approval.

[DaBestCode]

Approved after local and hosted verification. The SmolLM2 revision is pinned, the raw counters are internally consistent, the compatibility language is appropriately scoped, and Ruff, formatting, mypy, tests, build, and GitGuardian all pass. Please mark the PR ready for review when you are ready to merge.

[DaBestCode]

Please rebase and I will approve the PR. Thank you!

[RezaAshrafii]

Rebased onto the latest main and resolved the documentation conflict while preserving both the upstream schema-compatibility section and the SmolLM2 compatibility entry.

The rebased head is 2e63065. Local verification passes: Ruff, formatting, mypy, pytest (43 passed), and uv build --offline. The branch is clean and ready for approval.

[RezaAshrafii]

GitHub created a new CI run for the rebased commit, but it is currently waiting for maintainer approval again because the branch is from a fork. The local verification is complete and the existing approval remains recorded. Please approve/run the new CI workflow when convenient.