benchmarks: record Cursor skill invocation results

[anusbutt]

Outcome

Records the 2026-08-15 Cursor benchmark for automatic GraphKeeper skill invocation across Composer 2.5 and Grok 4.6. The change is limited to one Markdown result file under benchmarks/results/.

Evidence

No failing test applies to this documentation-only benchmark record. The staged diff passed git diff --cached --check, and the final diff was inspected before commit.

Checklist

• Tests cover valid, invalid, and relevant security or performance paths. (Not applicable: documentation-only benchmark record.)
• Documentation and examples reflect every changed public behavior.
• Schema compatibility is unchanged, additive and documented, or explicitly marked breaking.
• Constitution principles and append-only/evidence guarantees remain satisfied.
• npm run build passes. (Not run: documentation-only change.)
• npm run typecheck passes. (Not run: documentation-only change.)
• npm test passes with no hidden skips. (Not run: documentation-only change.)
• npm run package:smoke passes and the tarball contains intended assets only. (Not run: documentation-only change.)
• sh -n scripts/validate.sh passes when the legacy fallback changes, and node --check templates/pre-commit passes when the hook changes. (Not applicable.)
• No secrets, credentials, telemetry, generated archives, or unrelated edits are included.

Compatibility and recovery

No runtime, platform, schema, diagnostic, or packaging behavior changes. Rollback consists of reverting the single documentation commit; no manual recovery is required.