swiftperf evidence

As of 2026-10-22 Asia/Shanghai (Batch B G4 fill).

The original five rules are blocked: no swiftc in the 2026-10-22 measurement environment, so there is no JSONL (none is invented). Each of those rules has a sp-*.md blocked stub. Three rules added 2026-10-23 (sp-dateformatter-hot, sp-json-decode-hot, sp-regex-hot) now have JSONL microbenches and stay hint. Not corpus-triaged. Policy: ../docs/evidence-policy.md. Root matrix: ../../../docs/rule-regression.md.