Add streamBlocks() that POSTs to /ocr/stream and parses the NDJSON response line by line with a dedicated ObjectMapper. Falls back to the old /ocr endpoint via the default method when /ocr/stream returns 404. Uses a separate HttpClient with 5-minute request timeout for streaming. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>