Claude-on-Bedrock already gets prompt caching via the AnthropicBedrock
SDK path. This adds it to the raw Converse API path used for non-Claude
models (Amazon Nova, and Claude when bearer-token auth forces Converse
routing, #28156) — a conservative model allowlist inserts cachePoint
blocks after tools, system, and the message before the newest turn, and
extracts cacheReadInputTokens/cacheWriteInputTokens into usage so cost
accounting picks them up through the existing Anthropic-style fallback.
Ref: relatorio-cache-performance-provedores-ia.md, P0 item 1.