[Mec-iS]

What

Make the 0.7.0 breaking change visible in the usual doc files:

• README.md: new Breaking changes in 0.7.0 section with a [!WARNING] callout explaining that datasets no longer enables std_rand, what seed behaviour to expect, and the two-line migration (features = ["datasets", "std_rand"]). Dependency snippet bumped ^0.6 → ^0.7. The dataset-generators bullet now mentions the fixed-seed default.
• src/lib.rs crate docs: short breaking-change note next to the features section, so it shows on docs.rs.
• AGENTS.md: the feature list claimed datasets implies std_rand and serde — stale since 0.7.0. Now says it implies serde only, with the migration hint.

Why

#416 (shipped in v0.7.0) changed generator seeding, but the only warning lived in CHANGELOG.md. Users upgrading a patch/minor will hit silent output changes (fixed seed instead of OS entropy) without this.

Checklist

• Docs only, no code changes (fmt + clippy --all-features pass in pre-commit)
• No new tag

[Mec-iS]

These changes are merged into the v0.7 release candidate on main (commit cd217dd). The candidate is undergoing benchmark tests in smartcore-benches run 40066233708; a measurement report will follow.