Document that BODY_AND_HEADERS makes response bodies larger than the preview single-read #18

The bounded-capture response wrapper keeps a body repeatable only when it fits within the preview cap (default 8 KiB, DEFAULT_BODY_PREVIEW_MAX_BYTES). For a larger body, source() is one-shot: it replays the captured prefix then continues from the live tail, and a second source() call throws IllegalStateException (LoggableResponseBody over-cap path).

This is documented on the LoggableResponseBody class itself, but not where a user actually opts in: HttpLogLevel.BODY_AND_HEADERS and HttpInstrumentationOptions. Code that relied on the previous always-repeatable drain-once behavior (calling source() twice on a logged response) will now throw for any body larger than the preview size once body logging is enabled.

Action

Add a sentence to the HttpLogLevel.BODY_AND_HEADERS and HttpInstrumentationOptions KDoc: with body logging on, response bodies larger than bodyPreviewMaxBytes are single-read (a body within the cap stays repeatable).

Code added on fix/http-stack-correctness-resource-safety (#13).