Clarify BorrowMe repeat evidence interpretation

[sjh9714]

What changed

• Clarified that the historical product-listing p95 23ms is an original README record without raw k6 artifact, not a current measured claim.
• Clarified that the current product-listing p95 358.1088ms is the 2026-05-23 clean repeat3 local k6 snapshot with preserved raw artifact.
• Updated README and supporting docs so interview wording keeps those evidence categories separate.

Validation

• git diff --check
• ./gradlew test
• ./gradlew build