chore(deps): integrate amplihack-rs v0.18.25

[rysweet]

Summary

• pin amplihack-agent-eval to the immutable source commit for amplihack-rs v0.18.25 (9ee05a06eab98e9ab504a031bffaa4190700c2af)
• add compile-time and behavioral compatibility guards for the linked gym API
• update dependency documentation and generated labels
• correct Simard's dependency-drift guidance so moving upstream main is a signal, while adoption requires an approved release or specific reviewed fix

Upstream verification

• annotated tag v0.18.25 dereferences to 9ee05a06eab98e9ab504a031bffaa4190700c2af
• the consumed amplihack-agent-eval subtree is byte-identical to the previous pin
• the crate's workspace version changes from 0.11.1 to 0.18.0; no transitive crates or API adaptations are introduced

Validation

• hooks/pre-commit
• hooks/pre-push
• Cargo Vet succeeds
• Cargo deny bans, licenses, and sources checks succeed
• strict exact-state review: zero concerns

Integration ordering

This pull request must merge before #4478 and #4826. Both will then merge updated main and rerun their checks before merge.

[github-actions]

📊 Coverage Summary

Generated by cargo llvm-cov --workspace --summary-only (nightly, excluding test files)

Module	Lines	Covered	Coverage
Total	215821	182528	84.6%

_{Coverage data from CI run. Test files matching tests?/ are excluded from line counts.}