* fix(master): honour -volume.fileSizeLimitMB on the master's /submit - #6748
`weed server -volume.fileSizeLimitMB=2048` still refused anything over
256MB, and the reason is not the one the report assumes: the option does
reach the volume server. The master does not use it. Uploads through the
master's /submit are buffered by submitForClientHandler, which passed a
hardcoded 256MB to needle.ParseUpload, so the master rejected what the
volume server it started would have accepted.
The limit is now passed in. `weed master` gains its own -fileSizeLimitMB
with the same 256 default, so a standalone master behaves exactly as
before, and `weed server` and `weed mini` hand it the value their volume
server already got.
* master.follower: take the same upload limit, and say which flag to match
Review found the follower left behind. It serves /submit like the leader
and buffers uploads under the same limit, but kept the fixed 256MB, so a
cluster raised above that would accept an upload through the leader and
refuse the identical one through a follower.
Two smaller points from the same review: the master's flag description
named only the standalone volume server's spelling, and now names the
weed server and weed mini form too; and the under-limit test asserted on
the error message alone, so it would have passed had the limit rejected
that payload with different wording. It now requires the request to get
past parsing.