Address c-review nits on the itemize/output feature:
- RSYNC_COMPAT.md: state that %b is the source length (always == %l) because
no wire-byte counter exists; keep Summary equal to the matrix (recounted:
54 implemented / 84 not-implemented, 147 rows total - four rows flipped).
- change_list.h/.c: document bytes_sent == size; note itemize/out-format lines
never interleave with each other but may interleave with legacy log
messages sharing the stream; mark the %M stat() path best-effort.
- change_render_format scan in format_uses_mtime now mirrors the tokenizer
(skips '%%' and unknown '%X' pairs) so a literal '%%M' no longer triggers
the stat() fallback.
- Integration tests: --list-only under -m; a changed file on a second
--incremental run emits exactly one '>f' line while unchanged files print
nothing; --log-file + --log-file-format under -m.
Implement rsync-style itemized output backed by one shared change-event
engine (src/client/change_list.c):
- -i/--itemize-changes prints ">f+++++++++ <path>" for files actually sent
(single-threaded and -m); unchanged files print nothing.
- --list-only prints an ls-style listing of files that would be transferred
without contacting the server or writing anything.
- --out-format=FORMAT prints a printf-style template per changed file
(tokens %%f %%n %%l %%b %%M %%%%; unknown escapes preserved).
- --log-file-format=FMT logs each transferred file when --log-file is set.
Events are emitted from the per-file sender path shared by both transfer
modes, so the single sender thread is the only reporter (no races).