Make .protocol report SIP content, not source-folder totals

[hyeeyoungkim]

Summary

.protocol reports the file count and byte size of the source folder, including files that
-excludedFileNames keeps out of the SIP. This makes data_stats() apply the same exclusion list
the packer already uses, so <files> and <size> describe the SIP. Three functions, about 5 lines,
nothing reordered.

The problem

main() writes .protocol before anything is packed:

create_protocol(data_in_path)   # calls data_stats()
create_xip(args)                # only during packing does include_files() apply -ef

data_stats() walks the source folder with an unfiltered rglob("*"), so excluded files are still
counted. The same return value feeds reporting_std_out(), so the sip_report dict handed to
callers like yesc_bulk.py carries the same numbers — reading sip_report instead of .protocol
does not help.

Example, on a folder of 7 files / 400 bytes, of which 3 files / 300 bytes are content:

$ yesc.py -i src/item_ao1234 -o out -export -sha512 \
          -excludedFileNames "Thumbs.db,.DS_Store,desktop.ini,.BridgeSort"

.protocol:        <size>400</size>  <files>7</files>     <- everything on disk
actually in SIP:  3 files, 300 bytes

Longstanding, and not specific to one branch: data_stats() is identical on all six branches of
this repo carrying yesc.py, and git log -S shows the call order has never differed.

The change

def data_stats(data_path, list_to_exclude=None):
    # only count files that will actually be packed into the SIP
    file_list = [name for name in Path(data_path).rglob("*")
                 if Path(name).is_file() and include_files(Path(name).name, list_to_exclude)]

Function	Change
data_stats()	new optional list_to_exclude; filters inside the existing comprehension
create_protocol()	new optional list_to_exclude; passes it to data_stats()
main()	create_protocol(data_in_path, getattr(args, 'excludedFileNames', None))

The same folder then reports <size>300</size><files>3</files>, matching the SIP.

getattr() rather than args.excludedFileNames because callers that import yesc build their own
Namespace, and a plain lookup would raise AttributeError for any that omit the field.

What this affects

• Without -ef: numbers unchanged, since include_files() returns True for an empty or
  missing list. Covered by test_data_stats_counts_everything_when_no_exclusions. Costs one extra
  call per file.
• With -ef: .protocol and the printed stats report SIP totals. Anyone reading the old numbers
  as source-folder totals will get different values; on a 300-item production batch the gap was in
  the file count only, bytes negligible, well under 1%.
• Callers importing yesc: both parameters are optional, so existing calls work unchanged, and
  sip_report keeps its keys and value types.
• More output with -ef: include_files() prints whenever it has a list to check, so those
  lines now appear while counting as well as while packing. Happy to guard them or add a quiet flag;
  I left them alone to keep the diff small.

What this does not do

1. Does not touch include_files(). It matches with if file_name in list_to_exclude, a
   substring test against the unsplit string, and its exclude_files = list_to_exclude.split(",") is
   never used — so "s.d" is excluded by a list containing "Thumbs.db". This PR only calls it and
   inherits that. Separate PR: pr/fix-include-files-fnmatch.
2. Does not move the .protocol write to after packing. Worth doing on its own, since
   .protocol is the watch-folder ingest trigger and a crash mid-packaging can point it at an
   incomplete SIP. But that is crash-safety rather than counting, and localAIPstr is created inside
   create_protocol() and used later by create_xip().

Only standard export mode is verified. data_stats() walks the whole tree, so modes that pack a
subset of it (-assetonly, -singleasset, --representations) may still over-count — no worse than
today, but not fixed here.

Tests

Six tests exist on my fork but are not in this PR: yesc.py ends with a bare
args = parser.parse_args(); main(args), so import yesc runs argparse and calls main(), and
pytest cannot load the module. pr/fix-import-guard fixes that, and these can be added once it lands.

Test	Covers
test_data_stats_excludes_listed_names	listed names are not counted
test_data_stats_counts_everything_when_no_exclusions	omitted, None and "" behave as before
test_data_stats_recurses_nested_subfolders	exclusions apply at every depth
test_protocol_matches_sip_when_exclusions_fire	end to end: .protocol matches SIP content
test_main_tolerates_namespace_without_excludedfilenames	the getattr() path
test_sip_report_keys_unchanged	sip_report keys and types are untouched