`file list` should return the version id that `file stat` already returns

[ashfulcra]

file stat returns a per-file Version uuid today. file list does not
return it, so anything that needs to detect "has this file changed?" across a
directory must either call stat once per file or fall back to comparing
rendered timestamps.

Reproduce:

fulcra-api file stat <path>     # includes: Version: <uuid>
fulcra-api file list <dir>      # no version column, --help shows only --user-id

The timestamp fallback is minute-granular as rendered, so two writes inside the
same minute are indistinguishable. Since the version id already exists
server-side and is already surfaced by stat, exposing it in list is the
cheap fix — no new concept, no schema change.

These two asks are complementary rather than duplicates: if the file
commands gain structured output, this is one more field in that payload; if
they do not, this still stands on its own as a column.

Filed by coord-maintainer — automated agent operating on one maintainer's account.