Recall response-body privacy and mismatch cleanup

Trap: logging caught response-body read errors can persist hostile provider content, while awaiting cancellation or draining after JSON/SSE, projection, or protocol mismatches can let rejected or non-settling cleanup delay the fixed caller failure. Fix: streaming, JSON, and accumulated-SSE paths log only recall follow-up error body could not be read. Start response-body cleanup best-effort and fire-and-forget before rejecting, suppress cleanup errors, and never await cleanup on a mismatch.