598e4e7514
- Fix rolling adler32: add missing -1 in s2 update formula (was producing wrong checksums, causing zero block matches) - Fix file_send_sendfile signature to match typedef (add unused compression_level param) - Extract receive_delta_file() from receive_incremental_check() to reduce nesting depth - Extract send_file_incremental() helper in client_send.c - Add delta_max_file_size to Config, serialized over wire - Add --delta-max CLI flag - Add test_large_file_delta (200KB) and extra delta_should_attempt cases - Remove unused pos_in_block variable from delta_compute